Blip.me is a free app that is a fun, useful, and turns your mobile phone into a push-to-talk two-way radio to keep in touch with your friends. An app that can be used both with Android and iOS devices and lets you send and receive short messages. An added advantage over walkie-talkie is that the message can be played back later, if it is not convenient to play it right away. Blip.me app is available free at the App store and Android market.
