Get the Whitepaper called The Grey Matter of Securing Android Applications. It starts with the introduction of the Android platform and fundamentals of the Android applications. It later talks about the in-built security features of the Android platform and the additional features that are provided by Google to build a secure ecosystem. It also includes how and why these features can be leveraged to build secure Android applications.
You can download it from the following link: https://packetstormsecurity.com/files/download/147088/The_Grey_Matter_of_Securing_Android_Applications_v1.0.pdf
Source: https://packetstormsecurity.com/files/147088/The-Grey-Matter-Of-Securing-Android-Applications.html