The idea is a children to install it on their parents devices and do nothing more. No smart watch, no need to the parents to frequently click anywhere. Just keep their device with them. I did it that way on purpose. To be as less intrusive as possible. The app stays there and run 24/7 and detect locations, moment of activeness and rest, sleep, and creates behavior patterns. If any of the pattern gets violated, it send a notification. I give an example: my father do a daily walk between 8AM and 10AM. If he misses that one I will receive a notification. If my mother fails on the street and she does not move for some time, I will receive a notification with the exact coordinates.

That simple ;)