Select the room you would like to delete, then press edit.
Once in edit mode, you will be able to delete that room using the "Delete Room" button.
The room cannot be deleted whilst it is still active, a room is active up to 15 minutes after the last person has left.
Please note, once a room is deleted it will no longer be accessible for anyone who has that room code.
You can also have the room close automatically when it has been empty for over 15 minutes but toggling this option on when creating a room.