I tested the UsynligO app this afternoon.
I uploaded a little map of the neighborhood and Holcom Park. The app worked perfectly.
I can see using it to set up virtual permanent courses.
It reminded me a little bit of the first GPS orienteering long ago. Paul S had about a dozen Garmin portable GPS devices. Back then, portable meant about the size of a hardback novel. The devices had a little text screen that gave you a compass direction and distance to the feature. If I remember right, each GPS cost something like $1500. The event was at Prairie Center.
I don't remember exactly when that race was. Wikipedia tells me that Garmin was founded in 1989 as "ProNav." It seems like the race was earlier, maybe 1988? Or maybe it was early 1990s?https://usynligo.no/about