Clockwork AutoLogger is a car performance app. You can measure the g-forces your car generates, the time it takes your car to get from one speed to another (e.g. 0-60), record lap times and dyno your car to compare the effects of modifications on power. You can also log performance data and play it back overlaid on a map. Buy the full version and get unlimited data log times and the ability to save and load tracks for the lap timer and cars for the dyno.