Fuffr uses Leap Motion-esque technology to turn the area around your smartphone into an extension of its screen. The motion-sensing technology is built into the case, which communicates with phones through Bluetooth. The prototype of the case can recognize various gestures, and would bring an interesting twist to iPhone gaming.
At this point, there's no word on when the case will be released or how much it will cost, and right now the company is giving away developer kits to interested programmers. The Stockholm-based Fuffr is also hiring for a bunch of positions.
Here's what it would look like playing "Flappy Bird" with a Fuffr case: