UX & Cross-Platform Mobile Application Development Frameworks

Transcription

1 UX & Cross-Platform Mobile Application Development Frameworks Esteban Angulo Javier Alonso Xavier Ferre 01/01/2014 Laboratorio de Ingeniería del Software Escuela Técnica Superior de Ingenieros Informáticos Universidad Politécnica de Madrid

2 Contents 1. Introduction Cross platform Mobile App Development Frameworks The pros and cons of Cross Platform mobile app design Advantages Disadvantages Classification according to categories Cross platform framework selection Detailed information of the pre selected frameworks Design for UX in Mobile Application Development UI Considerations Analytics for Usability Studies Google Analytics AppDynamics Localytics Distimo Countly Appsee Summary of the analyzed services Evaluation methodology Detailed framework evaluation criteria: Developer view Detailed framework evaluation criteria: UX expert view Evaluation Results PhoneGap Developer point of view UX expert point of view Analytics Integration Titanium Appcelerator Developer point of view UX expert point of view Analytics Integration Intel XDK Developer point of view UX expert point of view Analytics Integration Study results and conclusions References i

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4 1. Introduction Nowadays, the usage of smartphones and mobile devices has increased and become very popular among users having a supporting role on their daily activities [Di Giovanni et al., 2012]. People use mobile devices and mobile applications for reading newspapers, listening to music, interacting in social networks, playing games, chatting with family and friends, etc. There are many different mobile platforms available on the market and each one has different characteristics that make them unique such as: ios, Android, Windows Phone, Blackberry, etc. Therefore, the market demands the creation of applications that are able to work on all platforms to reach more users. The challenge for development teams all around the world is to be able to create and produce applications that can be used on several platforms. As each platform has different characteristics, at first sight, the approach is developing independent projects for each desired platform. This decision impacts on costs and resource consumption for the enterprises as more resources and a bigger budget is required. Cross-platform development frameworks offer a way of diminishing these costs. They allow the developers to create applications for multiple platforms and devices usually smartphones or tablets from almost the same codebase or from within the same design tool. The popularity of cross-platform development frameworks has increased as several frameworks have been released to the market offering cost-effective solutions [Humayoun et al., 2013]. In fact, cross-platform tools allow software companies to target multiple platforms, to reuse developer skills, share codebases, synchronize releases and reduce support costs. Despite the benefits offered by cross-platform frameworks for developing a mobile application, this approach comes with drawbacks as well such as performance, accessibility to hardware features, being updated with the newest OS upgrades, design challenges, user experience, having native look and feel. These factors can affect the development of an application and be the causes of a failed project because it do not meet the expectations of the targeted users. About the user experience, the challenge of using cross-platform frameworks is to provide responsive and fluid interfaces and interactions due to the fact of having restrictions or reduced accessibility to some specific resources (only in some cases) or due to the framework approach of managing or generating the graphical components of the applications. The user experience and its evaluation are very important and directly proportional to the subsequent success of a product. Performance and efficiency are crucial as well as the experience generated with navigating through the different screens of the application. The visual impact is also important and it is related to increase the users engagement. 1

5 Because of the popularity of mobile devices and their OS, the users have expectations about the behavior of an application and they have to be considered while developing an application and its interaction. This study is focused on analyzing the different cross-platforms available the points of view of a developer and a UX expert to evaluate its usage and features for being able to select the most suitable cross-platform framework that fulfills the evaluation criteria. To accomplish the objective, a research and a selection process was performed to discard some frameworks and reduce the list to the best three options suited to our criteria. Once the three final options were found, a test application was developed for being able to evaluate the usability of the product generated by each framework. 2. Cross-platform Mobile App Development Frameworks Cross-platform frameworks are tools that allow the coding and development of mobile applications to target several platforms without having specific project per platform. They rise as a solution to be considered when the applications should be run on several platforms. Most of them are based on the principle of coding once and being able to deploy the application in all the targeted platforms. Although the tools available in the market typically come with a write once, run anywhere promise, the amount of customization required for each platform s version can still be considerable depending on the interaction and the user experience desired. Also optimization of memory and performance is often limited which diminishes the potential of the app. Some of the frameworks offer drag-and-drop GUI design tools, and many incorporate APIs aimed at exploiting specific components like audio and GPS; quite a few are built around the Model View Controller (MVC) pattern The pros and cons of Cross-Platform mobile app design This section details the major advantages and disadvantages of cross-platform mobile app design based mainly in [Parker, 2013]: Advantages The most mentioned advantages for the usage of cross-platform frameworks are as follows: Wide scope (reusable code) Rather than having to write every specific action for each platform, a developer can just write the code once and then reuse it. The code developed can be reused as a primary reference for use in other projects to be built in whatever platform. 2

6 Easy deployment Deploying and compiling apps is much faster in a cross-platform scenario. This is especially true since various frameworks have cloud-based building tools. Easy for web developers (use of known technologies) Because most frameworks are based on dynamic or scripting languages, they are easier for web developers to jump in and use. Moreover, most frameworks also support HTML5 and CSS3 alongside calls to native functions. Plugins Some of the major frameworks offer easy access to modules and plugins that can easily plug into other services or tools. These also include offering common links to similar APIs, such as those for the devices cameras, accelerometers, or location sensors. Instead of writing unique code to talk to an iphone's GPS and a Samsung's GPS, one centralized set of code will be automatically modified to interface with both devices. Less need for platform-specific Organizations or companies to expertise can develop an app in many platforms without having to invest in a team or developer with platform-specific expertise. When deployment speed increases the cost decreases. The faster a developer can create apps, the less money it costs. This possible advantage is the one that could provide the most savings if it were true. Support for Enterprise and Cloud Services In addition to plugins and modules for specific functions, most frameworks also have the option to directly integrate with cloud services Disadvantages Using a cross-platform framework development strategy isn t always the ideal solution. Some tools have restrictions, the performance is not the same and the frameworks cannot always access to all the hardware features. Some of the disadvantages include: The framework might not support every feature of an OS or device If Google, Apple or Microsoft adds a new feature or releases a new OS version, the framework you are using will need to be updated to support those new additions. Given that the languages used are different, the communication "bridge" that the framework provides may not allow all pieces of information to go through. By using a framework, developers give up the ultimate control of how everything works in the app. Tools are restrictive You can t always use your own tools. Most frameworks mandate that developers use prescribed tools and suites limited to the software, and that can mean that users will 3

7 have to ignore their preferences and use something that they may have to learn all over again. Inefficient code Because the developer will not be working in each platform's native language, the efficiency of the final code will be determined by the efficiency of the translation engines in the tool. This may cause the final code to contain bloated code and inefficient coding techniques that a seasoned developer wouldn't use. Slower code and render time Related to the previous disadvantage, the code might not run as fast as the native one because the cross-compilation process can sometimes be slower than using native tools and calls for an app. Also, the code render time will be longer, because it will have to churn out code for each platform Classification according to categories There are many tools of different type available in the market and because the high number of these tools, the classification task is a hard task. We have considered the following classification [Banerjee, 2011] and [Banerjee, 2012] to group the frameworks into categories and inside each category we have detailed the framework s availability as follows: Mobile Web: These tools are primarily JavaScript libraries which in combination with suitable HTML5 and corresponding CSS render you mobile website on different types of devices. Some of these tools can work in conjunction with hybrid tool and the result can be packaged as a native application. Examples: Open source: iui, jquery Mobile, SenchaTouch. Visual Tool: They provide a visual interface where elements / widgets are dropped into the screen and the internal application plumbing is taken care by the tool. The result is either a native application or a mobile website depending on the tool. Examples: Free Version: Net Biscuits. Trial Version: AplicationCraft. Paid only: Kony, Verivo. 4

8 App Generator: In this category you have tools where you write your application in a specific language but the tool translates it into a deployable native application for different platforms. The deployable application may include a runtime engine or a virtual machine. The programming language varies from tool to tool. Examples: Open Source: Titanium Appcelerator, RhoMobile, Xamarin-Mono, MoSync. Trial Version: Flex (Adobe). Hybrid App: This category of tools provide a platform specific shell application which has the capability of rendering prepackaged HTML pages and extends the HTML capability through APIs which allow access to device specific features. Some of them include libraries to render platform-specific UIs. Examples: Open Source: PhoneGap, Intel XDK. Trial Version: WorkLight. Game Builder: This is similar to the previous category, but these tools are primarily targeted for game development. They have a much richer UI library and may even have 3D graphics capability. Some of them use special languages like Lua or LiveCode. Their crossplatform capability may extend beyond mobile devices. Examples: Open Source: PhoneGap, Intel XDK. Free Version: Unreal. Trial Version: Corona, Unity. Paid only: Bedrock Cross-platform framework selection This study initially started with a list of 18 tools of the 2012/2013 most popular cross-platform tools according to [Brown, 2012] and [VisionMobile, 2012] and grouped based on the classification shown above. We established the selection criteria under which all the frameworks were evaluated. All aspects are listed in the following list: Android and ios support. Well-known programming language. Open Source or Free versions. 5

9 Capabilities modeling the UI or IDE available. Access to device APIs. High use rate between developers. At the beginning, we decided to discard the paid and the trial version frameworks as well as the ones being too far from our goal, for example the frameworks for developing games. This filtering process reduced the list to 8 frameworks. Most of the remaining frameworks are mobile web oriented (HTML5/JavaScript based) and app generators (the final product is generated on native code) Detailed information of the pre-selected frameworks PhoneGap Apache Cordova [PhoneGap, 2013] - Mobile OS support: ios, Android, Windows, Palm, Blackberry and Symbian. Designed for JavaScript, HTML5, and CSS development, PhoneGap is now sponsored by Adobe and the Apache Foundation. The 2.0 version adds Windows Phone support, new command-line functions, and overhauled JavaScript libraries. It uses Apache s Cordova-JS API for tasks such as integrating PhoneGap code into larger native apps. It is an open source SDK focused on writing a native application exactly as if it is a website. Basically it is a container that allows developers to package programs implemented in a well-known programming language into native applications. In addition, it allows broadening the tool by adding your own plug-ins. It does not provide an IDE for development; developers have to write the code on the native IDE for each platform it supports (XCode for ios, Eclipse for Android, Visual Studio for Windows Phone). The UI is rendered in HTML. The tool does nothing to create the UI, you have to do it by yourself, using one of the existing HTML libraries, or building your own library. PhoneGap allows access to device hardware features such as accelerometer, GPS, camera, sound and more. PhoneGap won the People's Choice Award at O'Reilly Media's 2009 Web 2.0 Conference and the framework has been used to develop many apps, especially among web designers. Web designers become app developers with PhoneGap - Brian Rinaldi. Sencha Touch [SenchaTouch, 2013] - Mobile OS support: ios, Android, Windows, Blackberry and Web OS. Sencha s popular HTML5/JavaScript framework provides 50 built-in components, state management, and an integrated MVC system. It now offers a free native packager that streamlines distribution to stores like Google Play. This framework is free for use under the terms of their commercial license agreement. 6

10 It is a UI JavaScript Library which can be used by web developers to create UIs for mobile web applications that look and feel like native applications. Additionally it includes a set of GUI-based controls optimized for touch input. The framework can access to device components through the use of a native shell such as Cordova. Despite of a higher learning curve than most other web frameworks, it is widely accepted thanks to the great support for animations and touch events. jquery Mobile [jquery, 2013] - Mobile OS support: ios, Android and Web OS. Available under MIT license, this popular lightweight HTML5-based framework is built on jquery, and focuses on semantic markup, progressive enhancement, and customizable design. It has UI widgets that are touch-optimized and platform-agnostic. The jquery Mobile framework is compatible with other mobile app frameworks and platforms such as PhoneGap, Worklight and more. It s the leading cross-platform framework among Eclipse open source developers. Intel XDK (formerly known as appmobi) [Intel XDK, 2013] - Mobile OS support: ios, Android, Windows. The original version of XDK was released in April following Intel acquisition of the original appmobi tools in February. Actually, appmobi tools have been renamed and the company will position itself as a pure play cloud services company [Ribeiro, 2013]. The environment is available free, XDK lets you develop apps using the HTML5 foundation, the collection of standards that are intended to take the Web from being just static web pages documents to dynamic applications, then to give you a way to convert the dynamic apps for use on mobile devices. This framework has an on-screen emulator with a good range of options, so you can check the look and feel of your apps. There is also an apptester that lets you try the app out on a physical device. Once you are happy, the Intel Dev Center lets you package your app for different app stores. At first the framework didn t have an IDE, it was available in the Chrome Web Store as a complement, but after just a few months of revisions, the new Intel XDK resembles a fullfledged IDE with a new drag-and-drop interface to make it easier to create new HTML5 apps. It also has a more powerful framework that you can use to create designs that adjust to a device s native theme. AppMobi used the open source PhoneGap technology as the basis for its own HTML5 development product, so you can essentially achieve the same sort of app with both. 7

11 There is an extensive and growing community of tools and services that work with or on top of PhoneGap. Titanium Appcelerator [Titanium Appcelerator, 2013] - Mobile OS support: ios, Android, Blackberry and Tizen. It allows the development of native applications for phones, tablets and desktop applications through web programming languages like HTML, PHP, JavaScript, Ruby and Python. On January 20, 2012, Titanium Desktop was discontinued and became a separate, community-driven project. It has also been renamed as TideSDK [Whinnery, 2012]. Appcelerator claims its Android/iOS framework supports over 5,000 device and mobile- OS APIs. Unlike the more web-oriented frameworks, Titanium uses JavaScript to create native code, with claimed benefits in performance. JavaScript code can be used in the traditional sense for either application logic and for modeling the UI. Titanium Studio is a full open standard IDE that is derived from Aptana Studio which Appcelerator acquired. A remarkable feature is its platform-independent API to access native UI components including navigation bars, menus, dialog boxes and alerts, and native device functionality including the file system, sound, network and local database. It offers customizable metrics for actions and events. The application data can be stored in the cloud or in the device. Furthermore, applications can take advantage of the hardware, API access to native mobile functionality like geolocation, accelerometer and maps. This is a very popular platform among developers. Titanium gives its users access to more than 300 social, APIs, and location information services. RhoMobile [RhoMobile, 2013] - Mobile OS support: ios, Android, Windows Mobile, Blackberry and Symbian. It is designed for Ruby developers. RhoMobile is built on the Ruby language, the Rails Frameworks, and the MVC pattern. Its main objective is provide a high productivity level and development portability. In this case, as in the previous tool, the programming language used is not as general as others. However RhoMobile also supports modern HTML5 features. The final app develop requires a RhoElements license to run in a production environment. The IDE provided is known as RhoStudio, nevertheless it could be used another IDE like Eclipse, Visual Studio, Netbeans or other; the only requirement is to support HTML5, JavaScript, CSS and Ruby. RhoStudio allows building the apps on RhoHub (a new framework feature used for cloud app-building) without leaving the RhoStudio IDE. The 8

12 framework also includes style sheets customized for each device to give your applications a native look and feel. RhoMobile applications support access to device, system and framework capabilities through a common API. Xamarin Mono [Xamarin-Mono, 2013] - Mobile OS support: ios, Android, Windows Mobile. The code written in C# can be ported to ios, Android and Windows Phone using Xamarin very easily. Xamarin s C#- and enterprise-oriented package is compatible with a similar ios-based MonoTouch version, and can also share code with the C#-based Windows Phone. The last release includes Xamarin Studio, which bundled Xamarin s previous, separate ios and Android development tools into a single application and integration with Visual Studio. To develop the application s UI utilize the MVC design pattern. Especially to build native UIs, it uses different UI layers: MonoTouch.UIKit APIs on ios, Android.Views on Android and XAML/Silverlight on Windows Phone. Xamarin exposes a single set of APIs for accessing common mobile device functionality across ios, Android and Windows platforms. C#-flavored Mono for Android appeals to enterprise-focused developers familiar with Visual Studio. The platform supplies an environment conducive to Visual Basic developers, and is touted for its debugger and native binary compiler. MoSync [MoSync, 2013] - Mobile OS support: ios, Android, Windows Mobile, Blackberry, Symbian OS. The framework produces native mobile applications for multiple platforms using C/C++ and HTML5/JavaScript or any kind of combination of both technologies. The target groups for MoSync are both web developers looking to enter the mobile space, as well as the ordinary PC/Mac desktop developer with knowledge in C/C++ development. The MoSync platform can access parts of the native UI system on Android and ios devices since version 2.5, and Windows Phone devices since version 3.0. The MoSync NativeUI API has widgets for embedding webpages and OpenGL ES views in applications and all the UI widgets are handled from the same code base on both Android and ios. The following table contains a summary of the principal characteristics of the selected frameworks. 9

13 Type Language Availability Modeling UI IDE Access device HW PhoneGap Hybrid App HTML5 Open Source external JS-CSS libraries No Yes Sencha Mobile Web HTML5 Open Source/Paid JS-CSS (itself) library No Yes JQuery Mobile Mobile Web HTML5 Open Source JS-CSS library (itself) No Yes Intel XDK (appmobi) Hybrid App HTML5 Open Source external JS-CSS libraries or Drag&Drop interface Yes Yes Appcelerator App Generator JavaScript Open Source own API (native components) Yes Yes RhoMobile App Generator Ruby Open Source style sheets included Yes Yes Xamarin App Generator C# Open Source UI layers included Yes Yes MoSync App Generator C++ / HTML 5 -JavaScript Open Source Own API (native components) No Yes Table 1: Framework tool pre-selection summary table From this 8 frameworks, RhoMobile and Xamarin were discarded because they use Ruby and C# as programming language which requires extra knowledge and experience by the developer in comparison to the other ones which use traditional HTML and JavaScript as programming language. Sencha Tocuh and JQuery Mobile were also discarded as they have to be combined with other frameworks to allow access to the hardware API of the smartphones. Both are JavaScript based libraries for UI components and functionalities. The final selection list is formed by three general purpose cross-platform frameworks: PhoneGap, Titanium Appcelerator and Intel XDK. All of them were used to develop a testing application prototype to evaluate its performance and usability for developing and for the final product. 10

14 3. Design for UX in Mobile Application Development The main objective for using cross-platform development frameworks is to optimize the time spent on coding and generating the same application for the different platforms. In other words, coding once and creating several apps to reach all the targeted groups of users. Currently a lot of users have access to a wide variety of mobile platforms and the differences between each other are clearly stated. The users have expectations on the behavior of the applications according to the platform standards and an unexpected interaction or navigation can cause confusion among users. User s preferences, behaviors and reactions must be considered when designing and implementing the interaction on a mobile application. Usability and user experience are fundamental aspects to be taken into account in a mobile application development process. Having an application that offers a great user experience and is simple to understand can be a total success. For measuring the usability and also the usage of an application, it is necessary to include a tool that provides the necessary feedback to the developers for analyze the response of the users and the detection in advance the troubles that they may find during their interaction with an application UI Considerations The main objective is to provide the best user experience possible in order to engage the users to the application and facilitate the interaction and usage of the app. The problem arises when a frequent user of one of the mentioned platforms finds out that a specific application works in a completely different way of what he/she expected and is used to. If the expectations are not met, the user can feel frustrated and even stop using the application. According to Joseph Labrecque [Labrecque, 2011] some factors and paradigms must be taken into account at the moment of designing and developing the interaction on a mobile application. These factors are: Screen paradigm or how to manage the different screens of the app and the navigation throughout them. The hardware, it is not the same for all platforms and some options or actions does not behave and react in the same way. Gestures, the UI design and the interaction has to consider the usage of gestures in order to make easier the interaction between the user and the app. Both ios and Android have their own interface guidelines to consider when developing a native application. These guidelines have many differences and that fact must be considered at the moment of developing a cross-platform application. 11

15 There are three main approaches to address this subject. The first one is providing the same behavior and the look and feel according to the platform on which the application is running. The second one is having the same styles and the same look and feel on the application for all the platforms. And the third one is delivering an application with the same look and feel but customized to follow the specific guidelines for each targeted platform [Barea et al, 2013] Platform dependent Platform dependent approach consists on generating a different interaction for each targeted platform, following the platform guidelines and philosophy [Barea et al, 2013]. For adapting this approach to the cross-platform development framework environment, most of the solutions are based on style sheets (CSS) and images that have to be added to the application to generate the look and feel similar to a native app on each platform. To be able to use this kind of solutions, it is necessary to detect the device s platform in order to include the correct files and pieces of code to change how the application looks. UI libraries and frameworks can be used to obtain the desired look and feel. A customized solution can be done by the developers creating their own set of styles Own cross-platform This approach aims to keep the same styles and interaction on the application regardless of the targeted platform. The user experience is coherent between the targeted platforms. On the other hand, platform conventions are not followed; the application defines its own behavior and interaction flow [Barea et al, 2013]. This solution can benefit the development process as the styles have to be done just one time. As a downside, this approach can cause an unnatural behavior for the users. In this case, some UI libraries can be used or the development team can create the styles and interactions by themselves providing a new solution. The most important aspect is the usability level desired and the nature of the project Adapted cross-platform This approach is a mixture between the two previous approaches; it proposes the final product as an application with similar appearance but its interaction design follows the targeted platform conventions [Barea et al, 2013]. The user experience is better adapted for each platform meanwhile offering coherence and similarities between platforms. The downside of the approach is that some special features available only on one platform must be left behind [Barea et al, 2013]. In a cross-platform development framework, the approach would be creating specific look and feel and styles to maintain coherence between platforms but keeping in mind the consideration 12

16 of each platform. The usage of UI style libraries or plugins probably can be helpful to follow the platform conventions as those libraries can be applied to each platform separately Analytics for Usability Studies The usage of analytics and recording data about the products is usually associated to marketing, sales or business reports and it has been less common its use related to user experience, design and development of software product. Nowadays, this stereotype has changed, and many UX professionals have realized about the importance of having real data on which they can rely as a source to help them in their research and design decisions. The UX professionals and developers have to listen to their users but most of all learn from their users in order to be able to improve their experience and also improve the final product. The main question is what should be measured or which data and information is helpful and which one can be discarded. The recorded data can facilitate the understanding between the users and the developers. The information recorded about the behavior of the users is called analytics. There are many different services (SaaS) to record and generate several kinds of analytics for a mobile application. Depending on the needs and the characteristics of the organization, the selection of the service may vary. From the UX point of view, adding analytics as part of the development process allows the designer and the developers to take early actions and prevent problems, determine the causes that generate drops in downloads or sells and also provide information about the interaction of the users with the application. Registering and Implementing Analytics There are several possibilities or services to obtain analytics from the Apps. Several of them are paid and also not all are available to be used by cross-platform platforms, or they require the acquisition of a license or a service in order to be able to record the information and to generate reports. From all the available tools on the market, and after doing research and a selection process following specific criteria, the list for possible services to use was reduced. The analyzed services are the following ones: Google Analytics AppDinamics Localytics 13

17 Distimo Countly Appsee They have been evaluated under the following criteria: License: The service was evaluated according to its pricing. The desired one is a free service for applying in several studies. Services Provided: The information that is available or can be generated and stored by the tool. Compatibility with cross-platform frameworks: The service has to be compatible with the selected platforms. Generating valuable UX information: The service has to provide relevant and valuable information for UX proposes. A description of each tool is presented below Google Analytics This service is very complete and strong as it is provided by Google [Google Analytics, 2013]. It can be accessed from everywhere since it is web-based. Its usage is simple to understand and the reports can be customized. It allows the developers to have a lot of information about their applications such as: number of downloads, devices used, crashes, active users, recurrent users, among others. It offers special SDKs for working and integrating the Analytics platform directly with ios or Android applications. It also provides tutorials and dedicated information to the developers, and a complete interface to analyze the data generated with charts and graphics. This service includes a web part which can be used to insert the corresponding code on the cross-platform application if it doesn t allow the compatibility with the native Analytics SDK libraries. As this tool is well known and popular in the market and in the development mobile apps world, there are some third party modules or plugins to integrate the Analytics service from Google with the application that is developed in the cross-platform frameworks. For a usability experiment, the data provided may be not enough and a complementary survey or data collection would be required. On the other hand, it provides useful information and also real time features which can be used during the experiment to follow the behavior of the users. The service is focused on analyzing mobile applications and therefore the information provided includes the devices, the users information, application events and even a navigation flowchart 14

18 AppDynamics It is a new application and currently is on its Beta state. It can be used for web applications and mobile applications. This beta version allows the analysis of native ios and Android applications. It provides information about errors and slow transactions generating basic diagnosis and alerts. It has a forever free version and a quote version (Pro Version). It provides charts and graphs to deliver an analysis of user segmentation, device segmentation, and download rate, among others. According to the information provided in their website [AppDynamics, 2013], it should be used on transactional systems and they are introducing to the market their software for analyzing mobile applications Localytics It is a complete app used to obtain valuable data for marketing and analytics purposes. It provides several features such as: Real Time Analysis, User segmentation, Engagement analysis, A/B Testing, among others. It is very complete and is mainly centered on marketing and financial aspects of the apps rather than usability purposes [Localytics, 2013]. The application also provides charts and graphics according to the official website. During the evaluation process, a demo was requested but it was not possible to perform it because there was no answer from the providers. Some of the biggest companies in the world are using their services in order to obtain relevant information about the performance of their apps. The main issue is that it is a paid application but according to their pricing plans, up to 10,000 monthly active users it is free. It provides a 30 days free trial Distimo It is a free service which produces and generates analytics about different applications. It is free for developers who want to analyze their own apps. It is compatible with ios and Android native apps as well as with cross-platform development frameworks like PhoneGap and Appcelerator applications [Distimo, 2013]. According to the information provided, there is no code insertion to start using their analytics software. The application provides different services such as: multi-level data sharing, notifications, no third party plug-ins required, automated data sync (from different stores) and automated translation of the reviews. 15

19 Important and big companies are using their services to manage their data from mobile apps. They provide also a conversion tracking analyzer, which generates information about campaigns and the places where the users come from. In our particular case (usability studies), this application basically can be used to determine the download rate, the rankings of our app, the revenues (in case of paid apps), reviews distribution, benchmarking of our apps, among others. As all the other analyzed options, this application provides charts and graphics to illustrate the different information that is available. The app is more focused on financial aspects rather than usability issues or user experience Countly Countly is a paid service, $69 (51 ) for 500,000 active sessions. This service offers total support for all kinds of smart devices and a framework to create an own SDK to be able to track the data. It provides a lot of statistics that allow the developers to understand the user behavior as well as the app behavior [Countly, 2013]. It provides graphics and charts that can be customized by periods of time (30 days, last week, 90 days, etc) and also provides specific analytics for different topics like: users, users loyalty, sessions, session s frequency, devices, countries, etc. All this information is shown by dynamic charts that can be seen in different periods of time. It also allows the creation of reports in PDF. As it is a paid service and does not follow the desired criteria it was not analyzed more in depth Appsee This service is really interesting and specifically adapted for usability evaluations. It works only with ios applications and devices. According to its website [Appsee, 2013], it provides several functionalities that can be used to produce important data for the experiment purposes in order to improve the user experience: User Recordings: Allows recording all the interaction between the user and the application. In this way, developers can find out where the users have more troubles to use their apps and where they can improve the usability level. Touch heat maps: The maps record all the interaction gestures between the mobile device and the user. Using this app, the developers can establish which parts of the screen are more used, which action buttons are ignored or where the best place to locate the action commands of the app is. Crash Recordings: This service can record if there was a crash and an unexpected close of the application caused by a failure. 16

20 Also the regular charts and graphics are provided to show the number of users who have the app, the time that they spend in the app, the device that they are using, etc. After performing the demo with a person of the Appsee company, these are the conclusions: For the moment, the service is only available for ios applications and ios devices, the service will be provided for Android at the end of the year or at the beginning of The most interesting functionalities and the differences between this service and many other analytics services or software is that the evaluators are available to record videos to follow the paths of their users as well as generating heat maps to check which the most tapped controls were. The functionality of recording buttons can be set according to the requirements of the experiment or the analysis. Not all the sessions are recorded; the users can set the percentage of sessions that they want to record. And also the conditions under which the videos are uploaded to the Appsee servers; this means, only when the user is connected to a WIFI network or always. Also there is a possibility to have a sort of script or table of contents on which the evaluators can follow the steps of the video and check on which part of the application are the users at a certain moment. Aside from the recording functionality, the 100% of the sessions provide information to be able to create the heat maps with the total amount of data provided by all the users of our application. It provides images of the screen and highlights the most used interaction points by the users; it also provides information about the percentage of interaction, the gestures used, the places that were tapped but have no interaction at all (this can be useful in order to determine the expectations of the users or to improve some functionalities or the usability of the app), etc. The service provides also the Analytics data, similar to Google Analytics information. From our point of view, the interface seems easy to use and easy to filter for finding the information that the evaluators are looking for. On the other hand, I also think that Google Analytics provides more complete and detailed information. Appsee also provides a Crash Report with detailed and video recorded information allowing the evaluators to check exactly at which point the app crashed or eve to detect the error that caused the crash of the application. About pricing, this service is free up to 1000 sessions. At this point is convenient to establish what a session is: A session is counted as the times that a user opens and works with the application. So 1000 sessions doesn t necessarily mean 1000 users; it means 1000 uses of the application per month. If in some case there are more sessions, the information about the 1001 session and beyond is not recorded. 17

21 It is a monthly service and the counters are rebooted every month but there is the possibility to upgrade the service for $250 per month to have more sessions. As a monthly service the upgrade can be done just for one or two months and then return to the free service. According to the information provided during the demo, the integration between the Appsee SDK and the native ios application is really simple and easy. There are also tutorials and documentation provided to implement it successfully. 18

22 Summary of the analyzed services The following table shows a summary of the characteristics and the evaluation results of all the services analyzed according to the evaluation criteria established. License Services Provided Cross-platform compatibility Valuable information UX Google Analytics Free # of downloads, active users, user segmentation crashes, devices, events Real time tracking SDK for ios and Android. Plugins available for cross-platforms Provides stats and charts about the usage of the app and also the download rate and behavior of users AppDinamics Lite (free for ever) Pro (paid) Information about Errors, Stalls, and Slow Transactions generating Basic diagnosis and alerts Mobile service in Beta. Allows analyzing of Android and ios apps. Information provided is not totally oriented to UX Localytics Free up to o 10,000 monthly active users. From it is paid. Real Time Analysis, User segmentation, Engagement analysis, A/B Testing, Push Messages, etc Supports all major platforms - ios, Android, Windows 8, Windows Phone, Blackberry and HTML 5. Charts and stats about the reaction of the user to download or buy the app. Not totally related to UX Distimo Free for developers. Paid for companies. Analyze competitors, track revenues and downloads, benchmark categorizations. Cross-platform adaptation, SDK easy to connect to all major platforms Focused on marketing than UX. Information not so relevant for UX purposes. Countly Paid Information about users, users loyalty, sessions, sessions frequency, devices, countries, etc Supports the major mobile platforms. Information related to UX and also to marketing of the applications. Appsee Free up to active sessions for 1 app. Paid for more sessions and more apps. User recordings, heat touchmaps, automatic events, conversion funnels, crash reports Compatible with native and crossplatform frameworks but only for ios. Totally oriented to UX. Provides real valuable information Table 2: Analytics tool selection summary table 19

23 Based on the results showed in the table above and after running a demo when possible, the final decision was to use Google Analytics as the main tool for recording and storing analytics data of the applications. This tool was chosen because of its characteristics, popularity and because it is optimized for mobile applications and can work together with the selected crossplatform frameworks. 4. Evaluation methodology The final selection set is: PhoneGap, Appcelerator and Intel XDK based on its availability, device hardware features, popularity and characteristics. One of the important factors to choose one framework was the availability of information for starting the development of an app from scratch. According to Ballve [Ballve, 2013], we conclude that usually the users do not care if the app is native or mobile-web as long as it is efficient and responsive. Users expect a high-performing experience when using mobile apps. For testing the platforms, we developed a test application prototype that would be developed on each platform to evaluate and test the user experience as a developer and also to evaluate the final product obtained, in this case the application. Another part of the testing process of the selected platforms was the inclusion of the Google Analytics on the testing app, to review the connection process and how is the interaction with the different platforms. The main objective of the app is to inform the user about bus schedules to go from Madrid to ETSIINF and from ETSIINF to Madrid. The timetables will be shown depending on the time and the geolocation of the user. This functionality will be used on a future project to add new features to the ETSIINF mobile application developed for Universidad Politécnica de Madrid. This test application allows testing functionality with a few screens and access to a device capability (GPS), with not much complexity Detailed framework evaluation criteria: Developer view From this point of view, we look at what a developer is interested about the tool to make an easier development. Some of the properties to have been taken in consideration are: IDE: The Integrated Development Environment available for developing applications. Language: The use of a common programming language is an important point to reduce the required skills for developers to develop applications. By this way, we managed to reduce the learning curve. Layout: Creation and distribution of elements. API: The accessibility to native APIs to compare how it is possible to access them from each tool. 20

24 Emulator: Emulator used by the framework to see the behavior of the application. Test: Ability to test in real devices. Build: The architecture provided for the development process of the application. Documentation: Information available in FAQs, communities, etc Detailed framework evaluation criteria: UX expert view In this case, the criteria to evaluate the frameworks are the interaction generated (its look and feel) and the framework s compatibility with Google Analytics (the selected tool for recording information of the applications). The objective is to evaluate the user experience, the interaction and the UI of the final application generated by each framework. The idea is to obtain the best user experience as possible trying to achieve a platform dependent interaction, look and feel. For each test application prototype developed, an evaluation was performed and the interaction, the UI and the connection of the framework with Google Analytics. These factors also have to be considered in the final selection of a cross-platform tool. 5. Evaluation Results The framework evaluation will be performed analyzing the user experience and the usability of each platform during the development of the above-mentioned application PhoneGap Developer point of view Based on the criteria listed above, the results obtained after using this framework are the following: IDE: This platform does not have one specific; you can choose your favorite. During the testing process, Eclipse was used (the native IDE for Android platform development). This does not mean that only an Android application is developed; the same code can be reused to obtain it for ios too, although it is not the native IDE. To prepare the environment to develop it is necessary to install the PhoneGap plug in or include the PhoneGap libraries into the project and native SDKs plugins, in our case Android SDK and ios SDK. Language: The code in this platform is written in HTML5, JavaScript and CSS. Common programming languages used by web developers. JavaScript is used to write the code 21

25 for the actions and interaction of the app; HTML along with CSS are used to create the elements on screen. Layout: After creating the elements, JQuery Mobile was used to render the desired UI. It is an extra library for all popular mobile device platforms that is based on JQuery. In fact this framework was part of the starting list on the cross-platform tool selection process; it is classified under the Mobile Web category. API: With this framework it is very easy, because there are plenty of specialized libraries on each element of the device. The developer only has to import the PhoneGap library and call the appropriate methods. Emulator: This platform uses the native emulator. Test: You can install the app developed by simply connecting a real mobile device to the USB port and running the app from the IDE. Build: The code is generated only once and using a service called PhoneGap Build which compiles the app to allow it to run on several platforms. The compilation process wraps the code generated with PhoneGap with native code to allow the app to run on different operative systems. Documentation: For things related with the API, there is plenty of information in the PhoneGap community. For specific information about plugins or other subjects, information can be found in development forums UX expert point of view In the UX area, this platform was evaluated according to the UI considerations, the user experience generated on the final product and also the testing performed with Google Analytics to collect information for the usage of the application. The design must consider and define the approach that would be used: platform dependant, own cross-platform or adapted cross-platform. The goal can be approached using JavaScript and CSS libraries to be able to generate the expected user experience. For the navigation, the natural flow of each platform must be considered. As the framework is based on HTML5, basically it is a web site adapted for mobile and in this case the designers and developers have to implement the look and feel as well as the interaction from scratch. Some of the design guidelines of the platform s providers must be considered for providing the best user experience possible and also for engaging the users to the app. If the interaction with the app is too complex or too difficult, the user may stop using the app and never come back. 22

26 On the other side, as it is based on HTML5, the look and feel can be designed and generated as a unique piece of art; this means, developers may not follow exactly the platform s guidelines in order to create something new for the users. Although this approach seems good and innovative, in reality it can be risky and may have a negative impact on the users Analytics Integration Regarding Google Analytics, there are several approaches to implement the connection between the app and the service from Google. The connection can be done including the JavaScript file obtained from Google directly and implementing the connection manually; another approach is using a plugin from PhoneGap. The first step is to enter in Google Analytics and create a new profile for the mobile app and to obtain the Key to be able to establish the connection between the application and the analytics service. All the possible approaches were tested trying to find the best solution: Including the JavaScript file: It didn t work properly because the documentation followed to do this implementation is out of date and also the platform presented some errors while running. PhoneGap plugin: In this case, the documentation is also not very clear and out of date. It seems that the plug in is no longer maintained by the company. The process requires the call and the inclusion of the plug in but without actually adding any file. The code has to be included for the starting the service and recording the information required according to the need of the app. In our case, some global functions to improve the development process and to create an easy way to call the functions. Once the plugin is imported, the appropriate code has to be added for start recording the screens and events from which the developers want to have information. After compiling the code using PhoneGap Build to add the plugin and generate the application for each platform, the apps have to be installed in the different devices and then they are ready to transmit the information from the application. The testing process is completed when the app is connected and transmitting information to Google Analytics website. To perform this test, it was used the Real Time functionality which shows the number of devices connected and the active screens at that moment. The complete information about the screens and the events that are recorded require some time for being processed by Google and for the users to be able to analyze and work with it. The information obtained is about the audience, the behavior, navigation on the app, events, and versions, among others. 23

27 5.2. Titanium Appcelerator Developer point of view IDE: On this occasion the platform has its own environment, an Eclipse-based environment that implies that it is easier to use for familiarization with the IDE. To use this IDE, it is also necessary to install and configure the corresponding native SDKs. Language: In this case the platform provides three ways of developing: Classic mode, HTML mode and Alloy mode. In classic mode all the application is written on JavaScript only. The Alloy mode is available since Titanium version 3.X and is a MVC approach for the classic mode. It follows the MVC pattern and in this case the view is coded in XML and TSS (sort of CSS), the controller and model in JavaScript. On the HTML mode, the application is developed, as in the framework above, using HTML5, JavaScript and CSS. During the tests the same code developed first time in HTML5 with PhoneGap was used (included) here, only need to remove PhoneGap plugin, adding the corresponding Appcelerator references and the application works in the same way. Also the tests were performed using the classic mode on which we realized that this framework adapts its functionality to native structures and components. Layout: In classic mode the elements are coded in JavaScript, because the IDE does not provide a GUI design tool. The visual tool is not essential for managing the screen elements of the app. On the other hand, the HTML mode works in a similar way as PhoneGap. There were problems with sizes of the elements on screens, since depending on Android or ios versions, the measures used are different. Android uses pixel and ios uses dip. The source of this kind of problems is that the framework displays the elements according to native configuration depending on the platform used. To solve the mentioned issues, we had to specify the type of measurement used, instead of leaving with default options. API: Many facilities for accessing to the mobile device resources as it happens in PhoneGap. Emulator: This platform uses the native SDK emulator. Test: You can install the app to a real device via USB. 24

28 Build: Titanium s IDE can compile the generic app into native applications for the different platforms selected. The main benefit is coding once and obtaining native code for each targeted platform as the final result. Documentation: There is a lot of information available in the Appcelerator community and there are a widely range of developers in FAQs forums which helps for solving problems UX expert point of view Titanium Appcelerator provides different modes for developing an app which are: HTML5, Classic mode (JavaScript) and MVC mode (also known as Alloy and it uses XML, JavaScript and TSS styling files). The characteristics of development are mentioned above in the Developer point of view. From the UX point of view, all the approaches are beneficial. The HTML5 approach has similar characteristics as the mentioned in the analysis of PhoneGap. As a summary it is worth to mention that the look and feel either native or customized can be achieved by CSS and JavaScript libraries. On the other hand, the usage of the only JavaScript mode comes together with a default native look and feel for the selected platforms. Automatically, the buttons and controls are adapted and located on the correct places, colors and forms as the design guidelines of each platform. In most of the cases, the navigation flow is totally native and is already implemented, it just require the corresponding code to activate the behavior or the options. Moreover, the Alloy mode (MVC) allows the introduction of TSS files where are located the options or properties to control the behavior and the look and feel of the elements in the screen as well as specific properties as color, size, etc Analytics Integration In this case there exist two possibilities to connect the application with Google Analytics. The first option is including a library open source optimized to be used by Titanium Appcelerator. After performing the tests, this library presented some problems because it is not optimized for Google Analytics SDK V2.0 that is the one for mobile applications. It only works with a Website profile and the analytics are not optimized for mobile devices. The second option is installing a module for Titanium s IDE which includes the required libraries to allow the connection between the app and Google Analytics. This module is available for free at Appcelerator Market and just has to be downloaded and included in the IDE by the developer. Once the module is included on the project, it is necessary to connect the app and add the necessary code to track the screens and the events during the usage of the application according to the needs of the development team. 25

29 The testing process with the module was realized under the two environments: Classic (only JavaScript approach) and Alloy (MVC approach). The module works fine in both of the mentioned approaches, the only difference is that the Alloy mode requires setting the tracker globally in order to be accessed from all the different controllers and being able to register the navigation steps and the events. Once the plug in is installed, the appropriate code has to be added for start recording the screens and events from which the developers want to have information. To prove that the application is connected and transmitting data to Google Analytics, the Real Time functionality was used in order to detect the number of devices connected and the active screen. One issue detected during these tests is that the information transmission has a delay of several minutes, which is already announced by Google, not all the movements of the user are tracked on real time but when the data is processed, everything is tracked Intel XDK Developer point of view IDE: The first version of this platform was an add-on that can be used together Google Chrome browser, but later the company created its own IDE. The user experience as a developer with the first version was poor because it complicated the development process. Language: The framework is also based on HTML5, JS and CSS, so the creation of the elements and associated events is the same as described in other HTML5-based frameworks. Layout: To create the application, the process is the same as the one followed with PhoneGap, and generally followed in any HTML-based framework. As a remarkable point, it has the possibility of use a drag and drop tool to create the elements on screen. API: As in the two previous frameworks it allows many facilities to access to the mobile device features. Also PhoneGap libraries can be added to this tool to access the device features. Emulator: This platform uses a particular emulator. Perhaps worst in terms of features and performance; on the other hand, this emulator allows the developer to see the final result of the application in a wide variety of devices and to change the orientation of the device (landscape and portrait). Test: Possibility of putting your files to the testing servers and run the resulting app on the device(s) without actually compiling and building it. This framework uses a 26

30 downloaded application to test the resulting apps created with the framework and hosted in its own cloud service. The testing application was called applab during appmobi time. Currently with the New Intel XDK the process is easier and requires the usage of Intel App Preview to launch the resulting application. Build: The IDE is the home base for all the projects. At the top of this new IDE a series of tabs are intended to mirror the stages of developing an app. The contents of the tabs depend upon the selected project. The options offered are: Develop, Emulate, Test and Build. The build tab allows the possibility to package installable apps for a whole range of mobile, desktop or web platforms. Documentation: On this aspect, due to the recent acquisition by another company, there is not much information about the new tool most of information is based on the previous framework but it is not valid now UX expert point of view The characteristics for implementing a native user experience are more or less the same as PhoneGap and Titanium Appcelerator in mode HTML5. It requires specific JS and CSS libraries to be able to reproduce the specific look and feel of the native applications according to the selected platform. The framework also provides its own set of libraries JavaScript and CSS which can be helpful at the moment of developing an application. As mentioned above, there are many factors and considerations that have to be made for generating a good product, in terms of UX. The user has to be satisfied and the interaction with the application must be as fluid as possible Analytics Integration AppMobi offered its own service for recording statistics called statmobi, which offered a plus at the moment of obtaining data from the users and analyzing their behavior. StatMobi was adapted to be used on any platform and to record some events automatically. Since the beginning of 2013, statmobi changed to be storeview but in theory offered the same service. According to the information obtained in the official appmobi forums, the service was temporarily disabled on February 2013 and some users experienced problems with the reports.[forumappmobi1,2013] Also, on April 2013, it was announced that the company was working on new features and new reports for their users.[forumappmobi2,2013] Moreover, in the documentation part of the official Appmobi website, there is no information available about the storeview service and its implementation on an app developed with the new Intel XDK. [AppmobiWebsite,2013] 27

31 The information available about integration between XDK and a Google Analytics plugin is very scarce. AppMobi always aimed the developers to use their own service of statistics and that is one of the reasons why there is not so much information about official plugins or third party plugins to integrate an app developed with XDK with Google Analytics. XDK also supports PhoneGap or Cordova in order to access to the mobile device features. It seemed as a possible solution to the analytics problem the usage of a PhoneGap plug in to be able to interconnect both sides. But as the information on the official XDK forum recall, there is no support to PhoneGap plugins yet; so that solution was discarded [ForumHTML5Dev, 2013]. Because of the facts mentioned above, it was difficult to perform the same kind of test as the ones done with the other two platforms. There was some issue with the service storeview and no data was recorded. Additionally, there was no possibility to use Google Analytics with a plug in and to implement the mobile service provided by Google. The solution implemented was developing a library or a plug in that may provide the interconnection between the Google Mobile SDKs (for both platforms ios and Android) and the application developed on XDK. Another possible solution that was applied and actually generated some data was the usage of the Google Analytics code for websites. The usage of this approach provided some information but it is not optimized for a mobile application and some important information may not be available; these facts can affect the following analysis and results of a user experience or a usability studies. 6. Study results and conclusions This study provides the comparison between several cross-platform frameworks to develop mobile applications for different OS s. Currently in the industry, cross-platform frameworks and cross-platform approach are in vogue with the aim of having the ability to create and develop applications oriented to different markets. The study mentions and highlights the pros and cons of designing and developing a mobile application based on a cross-platform development framework pointing out which are the considerations and factors that should be taken into account at the moment of selecting the development approach, native or cross-platform. The factors that should be considered are: support of native OS features, restrictions from the tools or frameworks, not always the same code works everywhere, development costs, reduced learning curve (use of known web technologies), building and deployment process. All this factors can be pros or cons depending on the nature of the software project and on the environment of the development team. It is wrong to think that the cross-platform approach means that the same code works automatically for all the different platforms or different devices. Most of the code can be reused, 28

32 but also it requires customizations in some cases. Moreover, depending on the framework that is used and also the nature of the application, some particular features or functionalities should be programmed specifically for a determined platform or environment and depending on the OS, some extra considerations must be taken into account. From the user experience point of view, there are two approaches that can be followed: same experience in all platforms or native experience for each platform. Regardless the approach taken during the development process, the cross-platform framework and extra libraries can be the best solution for generating an easy to understand and effective application for the users. Sometimes it is more important that the application works properly and provides the user a good feeling than attempting to create an application completely revolutionary. So, the designers and developers always have to keep in mind the idea of generating a fluid, effective and efficient application with the resources at hand. One important aspect for usability are analytics. Having the required information at the right time can be the difference between success or failure. Supervising the behavior and the interaction between the users and the application can be useful to detect problems in advance or to know the failures of the application and improve the next releases, always with the aim of offering the best user experience possible and to engage our users. Based on the evaluation criteria presented on this document, the frameworks selected of the detailed evaluations were: PhoneGap, Titanium Appcelerator and Intel XDK. For performing the testing process of each framework, a testing application was developed in order to evaluate the usability and the performance of the tools. As a result of the testing development and based on the user experience as developers and the final product obtained, the most suitable crossplatform framework to fulfill the evaluation criteria is: Titanium Appcelerator In the following table are shown the general results of the evaluation between the three final cross-platform candidates: 29

33 PhoneGap Appcelerator Intel XDK Target platforms (Android, ios) Programming language Yes Yes Yes HTML5, JS, CSS JavaScript HTML5, JS, CSS IDE available No Yes Yes mobile device APIs Access granted Access granted Access granted Project storage Local / Cloud storage* *Using PhoneGap Build service. Local storage Local / Cloud storage Debug on emulator Native emulator Native emulator Own emulator Debug on device Direct via USB Download running app from PhoneGap Build. Direct via USB Download the project from server and run on his own testing app Build Build in cloud service Build in the IDE itself Build in the IDE itself Documentation Platform specific relative to API Platform specific Platform specific but sometimes outdated User experience The same for all users. If native UX desired, extra libraries are required. Like the native one The same for all users. If native UX desired, extra libraries are required. Analytics available No Yes Yes Google Analytics implementation Third party Google Analytics Plugin Third party Google Analytics Plugin Google Analytics approach as a website Table 3: App evaluation summary table 30

34 7. References [AppMobiWebsite, 2013] AppMobi website, accessed Nov,2013, [Ballve, 2013] Marcelo Ballve, The future of mobile development: HTML5 vs. Native Apps, Aug, 2013, [Banerjee, 2011] Udayan Banerjee, Cross Platform Mobile Development Tools a comparison, Technology Trend Analysis, December 2011, [Banerjee, 2012] Udayan Banerjee, A Tool Comparison, Technology Trend Analysis, February 2012, [Barea et al, 2013] A. Barea, X.Ferré, L.Villaroel. Android vs. ios Interaction Design Study for a Student Multiplatform App. HCI International Posters' Extended Abstracts Communications in Computer and Information Science Volume 374, 2013, pp 8-12 [Brown, 2012] Eric Brown, Top 15 Android-ready app development frameworks, application-development-frameworks- [ForumAppmobi 1, 2013] Forum Appmobi, accessed Nov,2013, 7 [ForumAppmobi 2, 2013] Forum Appmobi, accessed Nov,2013, 59 [ForumHTML5Dev, 2013] Intel HTML5 Dev Forums, accessed Nov,2013, [Humayoun et al.,2013] Shah Rukh Humayoun, Stefan Ehrhart, and Achim Ebert, University of Kaiserslautern, Developing Mobile Apps Using Cross-Platform Frameworks: A Case Study,2013 [Intel XDK, 2013] Intel XDK, 2013, [jquery, 2013] jquery, 2013, 31

35 [Labrecque, 2011] J. Labrecque. UX Concerns across Mobile Platforms. UX Magazine. July, [MoSync, 2013] MoSync, 2013, [Parker, 2013] Joseph Parker, Consider cross-platform mobile app development tools carefully, Jun, 2013, [PhoneGap, 2013] PhoneGap, 2013, [RhoMobile, 2013] RhoMobile, 2013, [Ribeiro, 2013] John Ribeiro, Intel acquires appmobi for HTML5 developer tools, Feb, 2013, eveloper_tools [SenchaTouch, 2013] Sencha Touch, 2013, [Skerret, 2013] Ian Skerret, Eclipse Open Source Developer Report 2013, [Titanium Appcelerator, 2013] Titanium Appcelerator, 2013, [VisionMobile, 2012] Cross-Platform Developer Tools 2012 industry-first report, Feb, 2012, [Whinnery, 2012] Kevin Whinnery, The future of Titanium Desktop, Jan, 2012, [Xamarin-Mono, 2013] Xamarin Mono, 2013, 32