Edit a group
1. When you are in map view, tap on the name or your current group in de top bar.
or
1. Tap on the menu icon
2. Tap on Groups
3. Select the group you want to edit
4. Tap on the 
edit icon next to "Selected tags"
5. (de)Select tags by tapping on them
6. Tap on the checkmark next to "save"
⚠️ Important: you can only edit a group when you are the group owner.
To invite users, check the article 'Invite user(s) to group'.