Flutter uses machine vision algorithms to analyze hand gestures picked up by webcams. The company offers a somewhat popular Mac OS app that can be used to control media apps/services such as iTunes, YouTube, Netflix, and Pandora. Google is tight-lipped regarding what applications - PC, mobile, or otherwise - Flutter's technology and engineering team will be applied towards.
Interest in gesture recognition has been growing lately: this year has seen Intel acquire gesture recognition tech developer Omek, startup Leap Motion launch a PC motion sensor to much fanfare (but mixed reviews), Samsung provide a bit of gesture recognition support for the Galaxy S4 (i.e. Air Gesture), and Microsoft unveil a 2nd-gen Kinect (set to ship with the Xbox One) with better motion-sensing abilities than the original.