What the heck’s Quantum Legacy HD Turbo? I’m not entirely sure, to be perfectly honest, but considering it used to be £9.99, it’s definitely worth a punt at the new price of £free. The App Store description promises "ON-RAILS action with JAW-DROPPING GRAPHICS". Sounds good to me!
Compatibility: Requires iOS 4.3 or later. Compatible with iPhone, iPad, and iPod touch. This app is optimised for iPhone 5.