How can I keep track of what my children are doing during the day?
How old is your child? can you talk to him about his day?
You can install a simple keylogger for android program https://www.refog.com/keylogger-for-android.html
This program will tell you a lot. With Hoverwatch Android Keylogger, you’ll always know where your kids are. See where they are on the map, watch who they call and text to, and discover what they are up to with Hoverwatch etc.