1. Applying software product lines to multiplatform video games;Albassam,2013
2. Android Apps Submitted Per Month (September 2015). Available: http://www.appbrain.com/stats/number-of-android-apps.
3. Android Pay (June 2016). Available: https://www.android.com/pay/.
4. Appcelerator, Titanium (2013). Available: http://www.appcelerator.com/titanium/.
5. Apple App Store 2015. Available: http://www.apple.com/osx/apps/app-store.html.