A new version for MAC has been released! Now you don't need the fftw libraries anymore. Download it here
Growl Hero is a beta game that detects your Growls/Screams while you sing a metal song. Like Singstar/Rockband but it detects screams. It is a a free, open-source app for Mac (Linux version coming soon) developed by Uri Nieto as the final project for the course Music-256a, at CCRMA, Stanford University.
Rock on! Scream on! Growl on!