Một số link hay nên xem

http://rdcworld-android.blogspot.in/2012/03/how-to-get-own-mobile-number.html

http://www.androidhive.info/

http://vietandroid.com/

http://stackoverflow.com/questions/2033914/quitting-an-application-is-that-frowned-upon/2034238#2034238
http://thaihoanghai.wordpress.com/2013/06/08/multi-language-%E2%80%8B%E2%80%8Bin-android/