Send messages to contacts the have Facebook Messenger installed, chat with friends on Facebook, or use to simply send text messages; can also attach photos and locations to messages. Facebook Messenger might just be the messaging app that ends all other messaging apps. For the app allows users on Android , an  iPhone , an  iPad , and even Blackberry to share messages with one another in just about every conceivable way. First off, Facebook Messenger allows users to send instant messages to contacts that already have the app installed, much like Skype or Fring. The difference is that the userbase is likely to be much greater since there is a large number of active Facebook users, and thus larger group of people likely to have the app installed.   Facebook Messenger also allows you to access sent and received messages on both the Facebook Messenger app as well as Facebook itself

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Facebook Messenger: Free Text, IM Chat on Android, iPhone, iPad, and Blackberry