* Add sliders for setting greenery and hills preferences (so you can _prefer_ hills, rather than just avoid them)
* Add support for preferring particular surfaces (e.g. tarmac vs trail)
* Add support for creating distance-specific round-trip routes that pass through one or more waypoints (at the moment you can only specify a start/stop location for round-trip)
* Sometimes round-trip routing suggests some very complex routes which would be hard to follow when running. Some work could go into simplifying such cases.
* Improve the UI/UX, it's still quite fiddly, especially on mobile
* Cycling support
* Native mobile apps (there are already mobile apps for Trail Router, but they're basically WebViews)
* Offline routing support in the mobile app?!
* Direct sync'ing of routes to watches/Strava would be nice, but there's no open APIs for this yet.
If you have any other suggestions feel free to chip in!