The official Facebook Messenger is now available in BlackBerry App World. This app has already been available via OTA through Facebook’s website, now it is officialy  in App World. With this app you can:
Reach friends wherever they are with Facebook Messenger.
-Message a friend or start a group conversation
-Reach friends on mobile or web
-Get push notifications
-Know who’s seen your messages
-Attach photos to messages
Download via App World
Official Facebook Messenger Now Available in App World
