I have it on my ipod, its great!!, well for ten bucks it will give you a good laugh, they have shown it to be crazy accurate if you have the real weight and powertrain power loss % works like any other accelerometer and calculates hp and is very good on 0-60 and 1/4mile time, there is a video around somewhere where it is more accurate then the stick on the window type, and only off by I think .05 sec and 4 hp from an actual dyno run