RaceChip is pretty well known on this side of the pond... Shmee150 just did a paid commercial for them... but it didn't turn out like I thought it would. Made me think of this thread.
He also tested a Panorama with one of RaceChip app... looks pretty cool to me!
Motorvision(AutoMotor und Sport on Tv, sorry it's all in German) found +10% more PS and +12% more torque and the car used less fuel too.