Z31GOAT

I can plug the info that this app gave me into a 1/4 mile calculator, and the trap speed (which is the more accurate way to calculate power) is only off by 2.5mph from what my car actually ran at the track. I'm impressed! You need two things, a phone with a good g sensor, and you have to be able to plug in all the info the app asks for. The less accurate your car statistics are, the less accurate this app will be. Happy I spent the money.