So here is a series of video tutorial that will teach you how to hack as well as how to secure android application.
as well as building environment for security auditing.
Here are the tutorials.
About Android Hacking And Pentesting Video Series
Brief Introduction to Android and its Architecture
Chandrakant Nial:If You need the pdf file of (Brief Introduction to Android and its Architecture)i will send you, comment below your mail address.
comment below or drop email at firstname.lastname@example.org for any further query and doubt.