Looking at products like Gryphon or Circle, I feel like this should be pretty easy to do self-hosted. It's just firewall rules right? Anyone know of a good open source/self-host product I can do this? A phone app is not a requirement. A web interface is fine.
I'm kind of trying right now with PiHole and cron jobs but something prettier and more comprehensive would be nice.
I would second Adguard Home. They have a lot of presets for blocking online services. You can add persistent clients, which can be identified with MAC/IP, select the presets you want to disable, and also have custom block/access rules for those clients.
Cron jobs are mainly for enabling and disabling internet access by mac address on a schedule. I also like that these commercial products force search to google or duckduckgo safe search, and youtube to youtube restricted on a per user basis (which really could be done by mac address). I mean I can prob do all this with firewall rules myself. But a slick web interface would be cool.
In Pi-Hole you can define groups and add devices to them and then assign block lists to those groups. I'm not sure if all your use cases are covered. Maybe you can check their discourse to see if others have found a decent way. The web interface is quite nice from my point of view.
Nobody's a child in my home. But I do block porn and malware on a DNS level. I use Knot Resolver with a custom RPZ blocklist curated from multiple sources which self-update weekly. I don't use PiHole or Adguard Home because they seem too unnecessarily heavy