HelloTalk is a free app for social language exchange.
It is available on Android, iPhone, iPad and iPod Touch devices
The idea behind the app is to foment easy language exchange. Launch the app and meet people who speak your target language and want to learn your native language. Through text chat and voice chat, you can share your knowledge and learn from a native speaker for free. You can also share photos.
Since this article was originally published, many new features have been added to HelloTalk as it has grown into a worldwide user base of millions!