I think it's a pretty neat idea! Might have to get a few friends tomorrow and try it out.
One minor suggestion - when I went to the homepage using Firefox, I was a little confused how to get to the actual functionality. From a cognitive standpoint in the age of the internet, it's 'a lot' of work to scan through the list of supported platforms, realize your current platform isn't in that list, and guess that there's only a way to get to the real functionality if you switch to one of the platforms on the list.
Potentially, depends how it would look visually I guess. You could just display a little message saying the platform isn't supported yet and linking to the FAQ perhaps.
Our web app turns a crowd & their devices into a huge stereo system; all devices play same audio in sync.
http://SpeakerBlast.com
We think it's cool, but maybe people don't see it being useful? We use it at home to fill our house with audio.