Settings > Admins is who can run the web app. Players never see it.
Two roles
Owner: everything, including inviting admins, setting their squad scope and changing the club's details under Organisation. Whoever created the club is its first Owner.
Admin: the scheduling surface: sessions, players, dates, venues, squads and announcements.
Inviting someone
Tap Invite admin, enter their email and choose the role. They get an email with a link; opening it while signed in with that address gives them the seat. Until it's used you can Copy link to send it again, or Revoke it.
To hand the club to someone else, or before deleting your own account as the only owner, invite them as an Owner.
Squad scope
An Owner can limit an admin to particular squads. They then see only the sessions, players and dates for those squads. Clear puts them back to the whole club.
More than one club
If you run several clubs, one sign-in covers them all. Click the club's name at the top of the sidebar to switch.