A mixture between Vine and Phhhoto, the new app lets you quickly and easily create a 1-second video that loops together 5 burst photos, playing them back and then immediately reversing the sequence for a "Boomerang" effect.
The app automatically saves the 1-second GIFs as a video on your camera roll, and the interface is simple and uncluttered - porting you directly to the camera screen upon opening up the app. When you've finished shooting a video with Boomerang, you can then share it directly to Instagram of Facebook, which is the only place your friends will see it as the app doesn't include its own dedicated news feed.
Here's an example of what a "Boomerang" looks like.
You can download Boomerang for iPhone over at the App Store, or for Android over at Google Play.