The trick to seeing your Facebook chat window in full-screen mode.
View Facebook Chat Full-Screen

Is Messenger better than email? We compare the two.
Why did Facebook Messenger suddenly turn everything purple. We investigate.
Is texting a better choice than Messenger? We compare.
Love Messenger but hate Facebook. I've got the trick to using Messenger without a FB account.
Facebook Rooms lets you hold group chats with people even if they don't have a Facebook account.