Zero Dot is an app created by Panos Dentsas, a Greek android developer, to help people that use zero facebook (0.facebook.com) get the most out of it.
Zero Dot adds new features to the standard free facebook service and it works similar to Facebook messenger but without any data or wifi connection! That means that you get notifications which include the other user’s name, the time the message was sent and of course the message itself along with sound notifications when new messages arrive, immediately without having to take your phone out of your pocket to check for any possibly new messages every once in a while.
Play store link
https://play.google.com/store/apps/details?id=com.orionapps.zerodot