I am one of those people who has a child in their life and is struggling with the "phone or no phone?" question.

My partner and I said, let's get the boy a phone so he can call us or Signal us when he needs to. But we both agree -- no need for many other features on it.

We looked into our mobile provider's parental controls -- it's $10 a month and involves installing apps.

So we went to F-Droid and found this: https://f-droid.org/en/packages/io.timelimit.android.open/

works quite well!