One of the most popular iPhone games ever, Tap Tap Revenge now has a fourth edition, which is free to download from the App Store for the first time.

Tap Tap Revenge 4, which, for the unseasoned, is akin to playing Guitar Hero on your touchscreen by tapping the musical notes as they reach the bar, has been wildly successful since debuting as one of the original iPhone games.

The fourth edition features over 100 songs from artists like Katy Perry, My Chemical Romance and Linkin Park and, naturally, Lady Gaga.

There's also a host of new social features which allow you to share your high scores with the online community via Twitter and Facebook. You can also "Like" tracks of your choosing.

Tapulous, which is now owned by Disney, has also added an "Arcade Mode" which presents more challenging obstacles to achieving note-for-note perfection, while the iOS 4 upgrade improves resolution for the Retina Display and Apple's new Game Centre.

Check out how the new, free edition, looks in the video below.

Link: 9 to 5 Mac