@somerandomperson For Android, the best I found is RethinkDNS with firewall

1. Select your preferred DNS blocklists
2. Block ALL apps using data including system apps
3. Set Firewall to block all Apps when not in use.
4. Select apps that CAN access data
5. Select apps that bypass firewall rules i.e. emails etc. This allows background data to keep you up to speed.

There is far more to each of the points Read read read then go. Anything can be rolled back in settings if any anything breaks