Apple's parental controls are close to useless. I wanted to give my kids access to a computer with just a few allowed websites, but it turns out that is almost

Apple's parental controls are close to useless. I wanted to give my kids access to a computer with just a few allowed websites, but it turns out that is almost impossible. Apps like Spotify are randomly blocked by web site whitelists, and sometimes they are unaffected... it's clear that no-one who actually has kids is working on parental controls. (No before everyone chimes in telling me I shouldn't filter my kids internet: if I don't they'll use the computer exclusively for watching the dumbest YouTube videos ever made. I want to give them access to a computer for doing productive things, not just another device for watching video)