Clonk Rage, I’m not sure if this counts as it originally wasn’t open source, but it’s not developed further and the creator released the source code for all games of the Clonk franchise. Source: almost 2 years ago

F2P as it will never cost anything. Else anybody could add all freeware, Open Source, abandonware and shareware games. For example go to clonk.de and download all versions for free (except openclonk). Source: almost 3 years ago

I am an OpenStreetMap enthusiast since 2013, before, I was very much involved in a PC game called OpenClonk (and before that Clonk) in my free time. Source: about 3 years ago

I modified an open source GPX recording app called Trackbook to turn it into a 24/7 recorder, and I wrote about it here: https://voussoir.net/writing/obsessed_with_gpx I have a few recent commits in my repository that I haven't put into a versioned APK yet though. The output GPX files can be viewed on the PC with JOSM: https://josm.openstreetmap.de/. - Source: Hacker News / 6 months ago

JOSM has quite convenient merge/split functions, making deletion and re-tracing unnecessary. I took care of the issue in https://www.openstreetmap.org/changeset/134052747. Source: about 1 year ago

Record your track and upload it onto Open Street Map. That's the map service that Strava and Garmin utilize. You'll be able to add the trail for everyone to see regardless of the program as long as it uses OSM. JOSM is a really good program to edit OSM and here's a video to get you started on how to use it. Source: over 1 year ago

Great for preparing data for OSM, but JOSM is the only desktop editor for actually making contributions. Source: over 1 year ago

One that comes to my mind would be JOSM: https://josm.openstreetmap.de/. - Source: Hacker News / over 1 year ago