Available for Android, Garmin Mechanic is an app that learns as much as it can about your car. When you're on a trip, the app can calculate total distance, average speed and estimated mileage.
When you pair the app with Garmin's ecoRoute HD module ($US90 accessory), the app will be able to read real-time performance data and show live gauges, throttle position, intake pressure and more. It's like transplanting the brain and dashboard of your car into your Android phone. [Android Market]