Facebook As you probably already know, it's almost exactly like if you use it on your computer. Stay connected with your friends 24/7.
Facebook Messenger Pretty much Facebook Messanger is a fast way to get into contact with friends and family. You can send and receive messages with anyone from you contact list.
Go!Chat for Facebook Go!Chat is like other messangers only you can only directly contact you're facebook friends that are online. Like on your computer, you can still send over links, videos and photos.
TweetDeck (Twitter, Facebook) TweetDeck links all your social networking devices together. Post to Twitter, Facebook, Foursquare and Buzz and they will pop up on your other profiles.