This works great if you are running iOS v4.0. Yes it cashes on v4.1, but the Developer has notified Apple of the crashing issues and it should be fixed when v4.2 comes out. Once this is fixed youll love this app. If youre not on v4.1 yet, Id buy it, but if you are, you should wait for an update to resolve the crashes.
LastCalling about PlaceTrack