Sites, books and other resources for creating client-server applications, do they even exist?

Question

Android

I have been developing on the Android platform for a long time, I read several books, but unfortunately they describe only simple applications, I did not see any in which the process of client interaction with the server was described, there are examples on the Internet, but unfortunately without proper interpretation, www .androidhive.info/2012/01/android-login-and-reg... , I found the only normal code with explanations, but unfortunately you can’t go further than registration + authorization, what would you advise for these purposes?

Answer 1

The example is good enough, though synchronous.
What exactly are you having problems with?

Answer 2

Tormented by a similar question. B. Hardy, B. Phillips. Programming for Android. For professionals. C 420 pp. client development for api flickr, good client example