One of Facebook’s latest moves, which royally annoyed a lot of people, was that they killed off chat functionality in their Android app. As an alternative, Facebook released what we know today as Facebook Messenger, which as its name rightfully implies, takes the place of the aging Facebook app feature.
Disadvantages of Facebook+Messenger installed at same time: HUGE battery drain and RAM consumption, device may slow down etc. (especially low-end devices)
Advantages of Facebook Chat Enabler: It's only an enabler and is never executed by the system, meaning no battery drain/RAM consumption/resource eating at all. (Facebook app itself drains battery)
Facebook Chat Re-Enabler basically does what its name implies. It re-enables the chat feature on the Facebook app. Removing such a feature should have resulted in a supposed drop in app size when the feature left the scene. However, it did not and the real reason behind it is because the Facebook team basically made it dormant as opposed to removing the code altogether. AntaresOne’s fix basically re-enables this functionality. The advantages of taking this route are that you now have about 17 MB more of storage at your disposal and you no longer have to worry about this thing draining your battery. This app runs once and voila! Chat is back in all of its glory.
The fix has been confirmed to work for versions 126.96.36.199.15 and 188.8.131.52.12, which happens to be the latest on the Playstore (as of the time of this article at least) and it is compatible with Android 2.3 all the way to the debuting Lollipop. Feedback for other versions of the app is highly appreciated. So, if you have any, please drop by and leave a few lines. You can find more information in the original Facebook Chat Enabler thread ! !