Today, software engineering research focuses on traditional software systems like the Firefox web browser or Microsoft Windows, which take years to develop and teams of designers, developers and testers. Software engineering is rapidly changing though. Emerging domains, such as mobile devices, are growing rapidly and depend heavily on new software operating systems like Android and the applications that they run, commonly referred to as apps. Over the past few years, we have seen a boom in the popularity of mobile devices and mobile apps which run on these devices [3]. Recent market studies predict that the global mobile app economy is expected to be worth $143 billion by 2016 [16]. Thus there exists considerable motivation for the research community to solve the challenges faced by the mobile app developers.

However, unlike traditional software, the distribution mechanism for mobile apps are very different ? they are released through app markets (e.g., Google Play and Apple’s App store). The key differentiating factor in an app store is that it is a democratic platform, i.e., both large companies with established products Adobe Reader from Adobe, and Timberman from Digital Melody (a company with 5 employees1), can release their apps through the same mechanism for the users to download and install. The data that these mobile app markets contain can be used by software engineering researchers to compile new empirical results that can help mobile app developers.

Additionally, the app markets allow users to post reviews of the apps. This is very different from traditional software. Mobile app developers get continuous feedback from users that can be leveraged to help them. For example, prior work leveraged user reviews to extract user-faced issues [11, 10], and new requirements [5]. However, today the review system for mobile apps is identical to that of books sold on an e-commerce website such as Amazon. While books are products too, they are very different from mobile apps in that books are not updated every few weeks like most mobile apps. Therefore in the case of books, the ratings and reviews collected for a book is all with respect to one version of a book, while the ratings and reviews collected for an app are about all the versions of an app. Hence the question arises whether the review systems of books is the best system for mobile apps or not?

Finally, the app stores provide a central location for all the apps, making it easy for researchers to mine the store for meta-data of the apps and the apps themselves [4, 25]. Using the data from the app stores, several companies like App Annie2, and Distimo3 have even built successful businesses selling intelligence gained from observing the evolution of several hundred thousand apps in the app stores.

Although Software Analytics is gaining popularity over the last year, with even a Dagstuhl seminar 4 in June 2014, much of software engineering research today is still focused on traditional “shrink wrapped” software, such as Mozilla Firefox, Eclipse or Microsoft Windows [18]. Recently however, researchers have begun to focus on mobile apps and the related software engineering issues. For example, the 2011 Mining Software Engineering Challenge focused on studying the Android mobile platform [22]. Other work focused on issues related to code reuse in mobile apps [19], monetizing apps through ads [21, 20], mining mobile app data from the app stores [8], testing mobile apps [14, 13], addressing device fragmentation [10, 6], resource usage and optimization [9, 17, 12], and teaching programming on mobile devices [24].

Even with all the above papers on mobile apps, there is no central venue to bring all the cross-disciplinary researchers together. There is therefore, a dire need for a community to be built around the line of research with respect to mobile app store analytics.
Hence, with a strong recent body of work like the one’s stated above, and the lack of a venue to build a research community around the challenges and opportunities, now is the time for a Shonan meeting on the issue of `Mobile App Store Analytics’. The proposed seminar would focus on research where the Mobile App Stores, and the data that they have are mined for insights into mobile app development. We intend to bring researchers in multiple disciplines from around the world in one place to discuss the future directions in the area of mobile app store analytics. Each of the researchers we intend to invite (Section 5), has conducted research and published papers on deriving insights from mining mobile app stores. Additionally the three organizers have prior experience in organizing successful workshops [15], research summits 5 6, and Shonan seminars. 7

In addition to the mobile app challenges that are currently being addressed in the research community, there are several emerging challenges that we plan to discuss at the NII Shonan meeting.
App development paradigm. Mobile apps are developed using several different paradigms – native to the mobile device platform, JavaScript based app engines, and HTML5. By analyzing collections of apps from several different paradigms, researchers can recommend
the paradigms that provide the best user experience.

1http://www.digitalmelody.pl/#our team
2http://www.appannie.com/
3http://www.distimo.com/
4http://www.dagstuhl.de/mat/index.en.phtml/14261
5http://msrsummit2013.se-naist.jp/
6http://msrcanada.org/msrvision2020/
7http://shonan.nii.ac.jp/shonan/blog/2012/11/19/software-analytics-principles-and-practice/

Feedback Mechanism. Given that users can directly provide feedback to the developers via the app stores (such feedback is publicly available for anyone to mine), how can the developers leverage this feedback? What tools can we build to help the developers digest the feedback and transform the user reviews into development tasks (fixing issues or building features).

Fragmentation. A major challenge that mobile app developers have to face is to deal with the fragmentation among different devices and OS platform versions, especially when dealing with Android devices [7]. We plan to discuss how fragmentation impacts mobile app developers and what software engineering researchers can do to help mobile app developers cope with fragmentation.

Changing role of developers. Unlike traditional software, mobile apps are often developed by very small or single-developer teams [23]. Therefore, the role of mobile app developers is very different than developers working on desktop applications, such as Windows and Eclipse. For example, mobile app developers often need to play the role of architect, designer, developer, tester, maintainer and even marketer or business manager. Therefore, we plan to discuss on how we can help developers effectively choose a business model (advertisement or in-app purchases based) considering both the reliability of the technology needed to implement the business model (libraries) and the revenue that it can generate.

Legal issues related to mobility. One issue that mobile apps have to deal with is that mobile devices frequently move to different locations. This mobility can cause legal issues (e.g., an app may be licensed to work in Asia, but not North America). Therefore, developers need to design their apps to deal with such legal issues. Can we learn from other apps in the store that dealt with such issues?

As described in subsection 4.1, we intend the NII Shonan meeting to have lively discussions about the various challenges in order identify the key issues that can be solved by academics. We also expect the software analytics researchers to be able to find suitable collaborators for the problems they decide to work on, among the other invitees that we plan to invite. As presented in Section 5, the researchers outside the domain of software analytics have worked extensively on research related to mobile apps ranging from static analysis to testing tools to energy analysis. We expect that these collaborations will push the boundaries of research with respect to mobile apps through many strong publications.

It is estimated that 1 in 8 software developers, develop mobile apps [16]. Such developers have developed over 1,200,000 apps in the Apple App store and over 1,300,00 apps in the Google Play store [2]. There are over 230,000 developers for the iOS platform alone in the United States [1]. With billions of dollars in revenue benefitting millions of developers and hundreds of millions of users, the impact of research on mobile app store analytics, and how developers can learn from other developers is considerable.

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