The problem: The school bus drivers do not know which students will be absent each day. In the PM, they are dropping off students whose parents may not be home. Solution: Keeping all the parties in real time connected loop. What platform would you use to solve the problem? An automated call center with dispatching or an App?.
It depends on the age of the students and the safety of the neighborhoods involved. For example, it would not be wise to have kindergartners handling smart phones.
If you could provide additional information, I could give you a more educated answer.