I could probably look this up myself but i see additional value in engaging with this new community.
The most important function i am looking for is house members can see and create markers/pins on the map for others to see and optionally accessible using ios.
Heck if you already host shared files for yourself and family you could set up shared josm file to sync automatically for everyone, although that might be too much, since people in the household/friends/whoever you share with might not want EVERYTHING shared