Twitter released their own video app earlier this year and it has exploded in popularity. It's the "thing" to have on your iPhone, and now it's out for Android, too.
Vine let's you share six-second looping video clips which get shared on Twitter. 13 million people have already signed up for the service sharing 12-million videos a day. The appeal of Vine is its simplicity. Users can shoot and edit clips by tapping the screen. Here's an example