On Sumdog, there's no School Admin account - all teachers have the same privileges.
To manage your classes click manage students on the right.
Every teacher on Sumdog can:
- invite other teachers to join
- accept a teacher's join request
- create student logins
- create a class... along with all other teacher functions on Sumdog.
This means that when the teacher who created the account leaves, the other teachers will have all the same privileges, including accepting new teacher requests.
Tip: See which teachers are part of your school on the Teachers page.