PubNub Chat Application
Developing a chat application in Android is tough. You need to have your own chat server, which is a pain to setup. It also requires your android app to handle your own HTTP requests and responses which requires AsyncTask. But to some relief we have Volley, Retrofit, Ion and other third party libraries to simplify the process. What if we don't have to do anything mentioned above and still get a super powerful chat application. Well that is where PubNub comes.
PubNub Chat Application is released under MIT Licence. See file LICENCE.