You need to use either iTunes, Spotify, Winamp, or Windows Media Player for your music playing. Anything else, such as Miro or Zune, is not currently supported.

Starting and stopping the music is at present the only thing Flutter can do, so look upon this as simply proof that the concept works. Apparently, according to the company website, next up in the pipeline is (currently for Mac OS X only) that allows you to change music tracks, simply by swiping your hand in front of the webcam. I'm sure they are also working on a version that increases and decreases the volume (at least, I hope so).

The pros to Flutter are ones that will appeal to efficiency freaks. If you're sitting in front of your computer typing away, and you want to change the track on iTunes, then you would have to stop typing, look for the mouse, find iTunes, then the track...that all takes time. But with Flutter, when you want to change tracks, you just stop typing, hold up a hand in front of the webcam, then go back to typing as the Rolling Stones track flips from not getting any satisfaction to singing about Angie. There's no need to click the mouse or to search for tracks. Your webcam and Flutter do it all for you.

Flutter has cons, though. Throughout the few weeks I tested this app, sudden hand movements at times started my Spotify desktop app. Supposedly Flutter should start Spotify only when I show my flat palm to the webcam, but I've had Spotify starting when I scratched my ear or swatted a fly away from my head. In subsequent tests, I failed to recreate this problem, so maybe it was just a temporary glitch. Nevertheless, when you have Flutter on, you should be cautious with your movements in front of the webcam. Plus, until the next version comes out, Flutter has only one function.

Despite these limitations, if you are a music fan who uses one of the supported music players, Flutter is a great app that gives you a glimpse into the future of what is coming and what is possible.