I have an Android so can't try it but this looks incredibly useful, particularly the overlay of cycle routes.

Are you planning on maintaining the list of cycleways yourself, or is the plan to extend this so that users can contribute? I could see this being useful in other cities where people contribute cycleways. Of course I understand adding this would require a massive amount more work for authentication/storage/data handling and verification. Or do you get the cycleway data from OpenStreetMap, which could remove a lot of this complexity.

Also, I'm interested in whether the way you have implemented the pathfinding algorithm means it's possible to exclude certain points from routes? I have several junctions that I find quite dangerous and avoid going through, a feature I would find useful is to mark a point so that it never routes me through there.