This is an unplanned post but I was so annoyed at having two Facebook messengers opened at once (my laptop and my mum’s tab.. he he) so being the dummy that I am due to exhaustion, I quickly searched the WWW on how to log out of Facebook messenger for the galaxy tab.
I figured it out on my own anyway, but these screen shots should help. The process may not be very explicit especially for new users:
Logging Out of Facebook Messenger from your Galaxy Tab 2
Step 1 Look for the “menu” icon at the bottom left part of your screen. It should look like this:
It will not work on the view presented above (new message screen) so you would need to tap on it while you are in the “friend list screen”
Please follow this link for complete article: http://excusemygeek.com/2012/11/06/how-to-log-out-of-facebook-messenger-for-galaxy-tab/