I use this: https://www.f-droid.org/packages/com.best.deskclock/
The funniest answer I saw to the question of the most privacy respecting clock was “a sundial”, but thats just my childish sense of humour.
Like NextDNS,there’s a very good range of blocklists to choose from but the firewall part is easier to set up and play with. My use case is as the app on my mobile phone and tablet. You can use the DNS element alone as you would with NextDNS and specify that for other devices. It took me a while to definitely move from NextDNS to Rethink. I went back and forth a few times.
And so the last steps to privacy are removed.