iCreate: "On your marks. Get set. Tilt! GTS is a racing game that uses the iPhone's accelerometer to control every aspect of game play. The whole game runs with the phone turned horizontally. You tilt the phone forwards to accelerate, back to brake, and left and right to steer. The controls are very intuitive and the game makers have built in a failsafe to stop people having the phone tipped too far forward when accelerating, which comes in the form of a pink screen with a 'Too Flat!' warning. There is a range of gameplay options: Single Race for quick bursts, Challenge Cup which features 16 racing circuits, Challenge Tour which will have you racing a total of 64 times and Championship that will have you battling it out 16 times. There are four difficulty levels that not only increase the competitiveness of your opponents, but make each track that bit trickier too. On top of this you have to finish at progressively higher positions to complete each stage at each level. GTS is great value for money, offering a multitude of levels and races to keep you busy for hours on end."