[kornhole]

I am not closely familiar with those features, but I can suggest something to explore. Many mapping applications are now built atop https://www.openstreetmap.org including Organic Maps and OSMand both found on F-droid.org. OSM.org can be edited directly through their website and with companion apps called StreetComplete or Vespucci. Other FOSS apps out there may have the specific features you desire, and if not, can be built if you suggest them to the projects. I do use bookmarks in Organic maps arranged in different lists which can be exported to KML file. I have not attempted to import them to another application.

[knoblauch]

Thanks for your answer! OSM is awesome, I use OsmAnd+ and have just discovered Organic Maps recently. I still haven't found a project that can do what I'm looking for, after trying uMap, Mapotic, RideWithGPS, Maps.me, mapy.cz, Bing Maps, MapQuest, Organic Maps,and others. So I might try and hack together a custom solution with KML export/upload.