What are the best apps for blocking websites on my kid's phone?

my son keeps finding ways around the restrictions we set and i’m worried about what he’s seeing online. we’ve tried a couple of basic controls but nothing seems to stick for long. what apps actually work well for blocking sites without being too easy to bypass?

Most apps that claim “unbreakable” just need proper admin/MDM setup and a quick physical install—pair your OS controls (Family Link or Screen Time) with a DNS filter like NextDNS on your router, since that blocks sites before any browser or sneaky workaround can even load. Kids will always test the edges, so a clean one-time setup plus occasional password resets beats playing IT detective 24/7.