For those unaware, Facebook Messenger is very useful application that separates the chat function of Facebook from the same Facebook . In other words, the application allows you to communicate with your friends on social network without the need to even open your browser!
More specifically, you can chat or it sends messages to your friends to see the latest updates on the top of your contacts online (just like in the Ticker) and receive the Notifications you.
The application can be downloaded from here and not have to worry about future updates as everything is done automatically.
Source [ Facebook ]