Design for the teacher’s hand
Four large status targets—present, late, absent and excused—are faster and safer than a tiny select menu while standing in front of a class.
Queue by class and date
Each unfinished or unsent register needs its own local record. Opening another class must never overwrite the first queue.
Make sync visible
The teacher should know whether the register is saved on the phone, being delivered or confirmed by the school server.
The useful test
Could a newly appointed member of staff follow this process without relying on somebody’s memory? If not, make the rule visible before digitising it.