Mark who is present, and the parents of the learners who are not get an SMS while it still matters. Nobody has to sit with a phone and a class list.
A teacher opens their class and sees the learners enrolled in it for this term, in order. Everyone starts present, so marking a register is tapping the few who are not, which is how a register is actually taken.
Streams are respected: a P4 A teacher sees P4 A, not all of P4. The same definition of who is in a class is used here, in marks entry and on the class list, so they cannot disagree with each other.
An absence is worth knowing about on the morning it happens, not at the end of term when a report goes home. When a learner is marked absent, the guardian on record can be sent a message the same morning.
That single message does several jobs at once. A parent who thought their child was at school finds out that they are not. A parent who kept a child at home knows the school noticed. And the school has said something useful to a family without anybody making a phone call.
Messages go to the guardian the school already has. There is nothing for a parent to install, sign up for, or remember a password to. It is an SMS to the number on the admission form.
A register kept daily becomes a record worth having:
That last one is the reason to bother. Children leave school gradually, and a school that can see it happening has a chance to do something while it still can.