Been on Strava for years and the heatmap is the feature I open the most. Watching my orange streets multiply is honestly more motivating than chasing a pace PR.
A few months back I got curious whether you could push that further. Like, what if closing a GPS loop actually claimed the area inside it, and someone else running through it could take it back from you?
So I just started building it. Spent way too many evenings on it. And finally works! The map above is a my daughters last run in Stockholm.
Some honest stuff I noticed once I started using it for real:
Closing a loop completely changes how you plan a route. I now run streets I used to skip just because they'd "complete a polygon". Pushes you to go new places. Defending territory might get tricky as well.
And it does not replace Strava at all. Segments, training data, the social graph, all that stay where it belongs. This is just a different brain doing a different thing on top.
Happy to answer anything. About the polygon math, the GPS smoothing rabbit hole (oh god that one), how I think about cheating, whatever. I'm the solo dev so it's just me here.