A wedding gift for my brother and his bride to be.
When sitting still it's a normal compass. When it's tapped or moved, it will get its position with GPS, send this to a server, and get back three bearings: the direction towards your house, the direction towards the companion compass, and magnetic north. Hold the compass so that magnetic north is under the red arrow and start walking where you need to go.
Based on the SparkFun asset tracker board