Here you go — https://apps.apple.com/us/app/mapcut/id6478268682. It’s really not supposed to be super nice, but good enough to have some active users. It’s free, so have fun! Sorry for putting it behind auth gates, I was experimenting with some other features that required webservers running.

Not the OPs app but there's an app doing something similar that I enjoyed for many years, you can also import from GPS trackers and others: https://fogofworld.app

Does that work like a game map where the fog disappears where you have been? That would be cool, although the reviews aren't great.

Yea that’s the idea. Worked well for the years where I tried it.

I use https://wandrer.earth/ , connected to Strava

Not OP, but https://dawarich.app/ seems to do the same (open source and self-hostable, also has an iOS App).