International Journal on Advances in Software, vol 12 no 1 & 2, year 2019, http://www.iariajournals.org/software/ 30 Current Progress in Cross-Platform Application Development Evaluation of Frameworks for Mobile Application Development Jan Christoph, Daniel Rösch, Thomas Schuster, Lukas Waidelich Pforzheim University Tiefenbronner Straße 65, Germany {jan.christoph | daniel.roesch | thomas.schuster | lukas.waidelich}@hs-pforzheim.de Abstract — Cross-platform development is increasingly driven devices, availability of network infrastructure as well as secu- by web frameworks. Modern frameworks typically support ap- rity and privacy issues [6]. The difference in devices also gen- plication deployment for different platforms as well as the crea- erates a variety of different resolutions and display sizes. tion of progressive web apps. This approach is also driven by the While developers are enacted to create and distribute ap- increasing number of different device types and platforms. De- plications in a large scale, they also have to deal with these velopment efforts can be significantly reduced by utilization of inherent differences and limitations of mobile devices (i.e., modern frameworks. Hence, several modern frameworks that battery life or small displays). Furthermore, it is necessary to have proven to be suitable for cross-platform development will address different operating systems (especially for be compared in this article. This article will extend our previous smartphones, and, to a limited extent, for feature phones as research on cross-platform development by several dimensions: at first, research on literature and technology developments re- well). Since the market for smartphones has consolidated re- garding cross-platform development is extended. Secondly, we cently, some operating systems (i.e., Windows Phone, Black- added further frameworks into our analysis. Thirdly, the evalu- berryOS and other OS hold a market share of 3.2%) vanished ation approach is systematically extended to discuss each frame- again. Still, to address the smartphone market, applications for work on an individual basis. This is driven by a reference archi- both, Android (market share: 72.4%) and iOS (market share: tecture and implementation. To create a sound and objective 24.4%) need to be provided [7]. In addition, Android is split framework comparison, the reference architecture is utilized to into different versions, manufacturers and various system cus- implement applications by means of each framework. Subse- tomizations. Despite vendor customization and just consider- quently tests for different mobile devices and platforms are de- ing the Android version, current most widely used is Oreo (8.0 fined. All frameworks are compared according several key met- and 8.1 with 28.3%), followed by Nougat (7.0 and 7.1 with rics. Finally, we describe current strengths and weaknesses of 19.2%) and finally, the latest version Pie (9; with 10.4%) [8]. all approaches before giving an outlook on future steps of re- In order to reach as many users as possible, applications search. need to support all major device platforms and versions of op- erating systems [6][9]. This introduces the need to either de- Keywords — cross-platform development; web component; velop platform specific or platform agnostic applications. web application framework; progressive web app. Platform specific implementations (native apps) literally re- quire almost as many application implementations as plat- I. INTRODUCTION forms that are intended to be addressed. Therefore, this ap- This article is an extended version of a former conference proach generates correspondingly high development expend- publication, see [1] for further details. Mobile devices have itures. On the other hand, with a more generic approach, a sin- become an important platform for today’s software applica- gle application or some core components could serve as the tions. Especially, the utilization of smartphones increased rap- basis for multiple platforms. Besides reduced developments idly within the last couple of years [2][3]. Since smartphones efforts, a generic approach also strengthens reuse of code and are often utilized to consume or orchestrate services, this pro- components. cess includes a vast range of applications. Smartphones also Currently, generic approaches can be further subdivided connect to other domains such as the Internet of Things (IoT) into Web and hybrid applications (see Figure 1). Web appli- and often utilize smart cloud-based services [4]. cations can be used virtually under any platform, as a Web The introduction of smartphones rapidly increased the browser is preinstalled on almost all devices. The most salient need and development of mobile software. The development advantage is application portability, which basically comes at of mobile software applications is a special case of software no cost. Web apps are typically optimized by means of Hyper engineering. Mobile applications are often also referred to as Text Markup Language (HTML5), Cascading Style Sheet apps, which implies that the application is intended to be used (CSS) and JavaScript [10]. Numerous frameworks (such as on a smartphone or wearable device [5]. Thus, development Angular, Bootstrap, React or Vue) provide additional func- must cope with specific aspects such as: short application tionality on top of Web standard technologies and help to lifecycles, limited device capabilities, mobility of users and speed up development of Web apps. 2019, © Copyright by authors, Published under agreement with IARIA - www.iaria.org International Journal on Advances in Software, vol 12 no 1 & 2, year 2019, http://www.iariajournals.org/software/ 31 Figure 1: Mobile App Technology Stack. Major disadvantages of Web applications are that they do we want to uncover innovations and differences that arise with not possess platform specific look and feel and often are re- the deployment of new frameworks and versions. We achieve stricted in functionality – especially access to system func- this with our reference app. The remaining parts of this article tions and device sensors. Furthermore, they must be inter- are structured as follows: First, Section II introduces the liter- preted and suffer performance losses compared to native ap- ature research method. This work can be seen as a starting plications [11]. point for further work on the article. Section III provides an Hybrid applications are built on frameworks such as overview of current mobile app development. In Section IV, Apache Cordova or Adobe PhoneGap. Often they rely on Web a reference architecture is presented and five framework- technologies also, and enact access to native device functions based implementations of this architecture are discussed. The and sensors [6]. Hybrid apps utilize a specialized browser to reference implementations are being evaluated in Section V. present the user interface (UI). This results in a presentation Finally, Section VI outlines the conclusion and outlook for layer, which is identical or very near to widgets used in native further research. apps. Today's hybrid framework technologies are mainly ex- tensions of Cordova and PhoneGap, as they extend and sim- II. LITERATURE RESEARCH plify the development of cross-platform applications. There- A comprehensive literature research was initiated to iden- fore, the frameworks Cordova and PhoneGap are not included tify significant literature on the topic of cross-platform devel- in the evaluation. While hybrid apps overcome some issues of opment and cross-platform frameworks. In addition, im- Web apps (such as access to system functions and sensors), portant scientific articles from the same field of research they still experience a loss of performance compared to native should be identified, which will form the basis for the later applications. However, it is notable that performance of hy- main part of the article. For this purpose, the proven literature brid apps has improved a lot with latest developments [6][10]. research of Brocke et al. [12] was used. A five-phase model is Comparing the short development lifecycles of devices and operating systems on the one hand to that of hybrid app frame- defined by Brocke et al., which enables a systematic literature works on the other, it is noticeable that the latest developments search. In the process, they combine approaches from Cooper are implemented with delays by the frameworks. As a result, [13] and Webster & Watson [14] . The method, the five-phase access to new functionalities can be gained earlier when de- process is shown in Figure 2. velopment is based on native apps. A. Definition of review scope Issues of supported functionality, performance and the ge- neric question of maintenance of cross-platform applications Phase I defines the different characteristic values of liter- lead us to the evaluation of multiple cross-platform frame- ature research. We apply the taxonomy of Cooper [13] in this works. With this paper we want to record the current state of phase as a basis. The applied taxonomy according to Cooper the art in the development of cross-platform apps. In addition, is explained below and also shown in TABLE I. The focus of 2019, © Copyright by authors, Published under agreement with IARIA - www.iaria.org International Journal on Advances in Software, vol 12 no 1 & 2, year 2019, http://www.iariajournals.org/software/ 32 this article is on research outcomes in the area of cross plat- TABLE I: APPLIED TAXONOMY OF COOPER