That's a wonderful idea. I'd also love to see challenges where your speed gets recorded at specific checkpoints and you have to set the highest average speed overall for the course.
App is now almost finished. Template needs to be redone as it's really messy and whole code needs a little clean up. (don't know what youtube did to video, it was much better before uploading)
You should make it so theres a mod that comes with it where you can travel in time (Using the map's time)