This is the Facebook Messenger for iPhone login page. Use your Facebook credentials to get started.
Full report: Facebook launches Facebook Messenger app for Android, iPhone by Emil Protalinski.
No numbers are required to message your friends: all you need to know is their name.
Group conversations are a go: you can message multiple friends at once.
Facebook Messenger also allows you to share pictures.
You can see where your friends are located on a map.
You can even get directions from Google Maps.
Facebook Messenger has all your messages from Facebook, not just ones sent or received with the app.