What is the functionality you are after as I am not familiar with aforementioned app?
As far as I know, it's mainly for tracking the location of family members who are also on the app and who have approved sharing location with you.
Exactly this. You can also pay and report incidents (e.g. robberies) in your area as well, although I don't use it for that.
I used PhoneTrack for NextCloud + the f-droid app long ago. I remember setting it up as a bit painful, but maybe it has improved. Judging by the screenshots it uses OSM.
https://apps.nextcloud.com/apps/phonetrack https://f-droid.org/packages/net.eneiluj.nextcloud.phonetrack/
I've never used it, but there's a location sharing plugin for OsmAnd that shares location via Telegram:
Unlike Osmand itself, the Osmand Tracker app is not open-source. While that's not a quality the OP asked for, I think it is important to note in this context.
Also, I found that Osmand Tracker drains your battery like crazy, but ymmv.
Everything #OpenStreetMap related is welcome: software releases, showing of your work, questions about how to tag something, as long as it has to do with OpenStreetMap or OpenStreetMap-related software.
OpenStreetMap is a map of the world, created by people like you and free to use under an open license.
Join OpenStreetMap and start mapping: https://www.openstreetmap.org.
There are many communication channels about OSM, many organized around a certain country or region. Discover them on https://openstreetmap.community
https://mapcomplete.org is an easy-to-use website to view, edit and add points (such as shops, restaurants and others)
https://learnosm.org/en/ has a lot of information for beginners too.
