"We love building things and playing games. So, we got together to build a network of fun, social apps for iPod Touch and iPhone, including Tap Tap Revenge, one of the biggest games on the iOS platform. We have over 35 million users and have been #1 on the App Store 6 times over, with Tap Tap Revenge 3 at #1 for 20 straight days, and Tap Tap Revenge 4 making it to #1 in just 24 hours! In February of 2010 we debuted Riddim Ribbon, a ground-breaking music racing game co-produced with will.i.am. Riddim Ribbon became the #1 grossing app on the App Store within 3 days after launch. We recently launched Tap Tap Revenge 4 for Android, our very first app on the Android Market."
Source: The Developer Website.