Another use case is documentation - as they do activities, the teacher will use their cell to snap photos of the kids doing stuff. They can then use the school's app ("platform", I suppose) to send out a short note/summary at the end of the day, which parents can read on their end in the parent app. Also, reminders about things to bring tomorrow, notices about upcoming activities, etc. I am assuming they use these documentation items at the end of the year for grading, etc.