Currently Account Owners can change permissions of apps so that they can edit and others can only view. When this happens other Account Owners on the Instance can not change those permissions. An Account Owner can lock themselves out of an app by simply giving someone else Ownership of an app and marking all others read only. Additionally when that Account Owners profile is deactivated the permissions are not released. (This happened when an Intern locked an app and then went back to school)
Useful feedback, thanks. I’ll check out the user account management workflow to see if there was a fix to this already existing, but in the meantime did you get admin access back?