Great one. I would love to have something like this for Hamburg, Germany as well. Or for the sake of [insert preferred deity here] for every city I have/want to travel to. Imagine sitting in the tube, watching the station you have to change on your smartphone and being able to find the shortest way.

Would be great.

One idea though: Imagine, you could show the normal start/end of a train on these maps, than you could decide beforehand, where in the train to sit, to reach the ideal exit.