Automobile Locator - This app has a rotating arrow that points in the direction of your car. It allows you to mark your cars location using GPS. You can then use it at a later time to help guide you back to where you parked.
Another great feature is the parking timer. It allows you to conveniently set an alert so that you don't forget about your parking meter that is about to expire.
This app works with GPS so some phones may experience problems if the app is not used outdoors or close to windows.