Badge(r)s!
www.badge-r-s.de
Free casual GPS game about creating, sharing, collecting and distributing virtual swag in the real world. Join, shape your environment, play with us!

it’s a bit rough in the ui/ux department and requires a google account but i had fun testing it today. you walk around to “produce” badges, which you can then “drop” wherever you are to make claims on map quadrants

found via https://weeklyosm.eu/archives/17334