Features of Facebook Messenger version 1.0
Send messages to your Facebook friends or friends in your phone contacts just by searching for their name.
See full history of all your messages, chats and emails on the app
Send messages to a group of friends and also add your location, attach photos to the message
Get notifications when you receive a message
Download the Facebook Messenger app for the Android (2.2 and above) and iPhone (iOS 4 and later) from the Android Market and the Apple iTunes store for free. This app is available only for United States as of now.