@openrightsgroup
Use either #Blokada or #Tracker control for DNS-level blocking of trackers. This will protect your phone system-wide, not just from your chat app.
For browsing, use #Firefox and the #uBlockOrigin plugin. Don't use #GoogleChrome: it's made by a surveillance advertising company and leaks data as badly as you'd expect — in fact, probably even worse. Google has modified Chrome to ensure that uBO can't be made to work well on it. (Search for "Manifest V3".)
And, yes, definitely use #Signal rather than some surveillance-Laden chat app from Zuckerberg & Co. Signal doesn't monitor your conversations or use them to target you with advertising or train an "AI". In fact, it shows no adverts at all.
https://blokada.org/
https://trackercontrol.org/
https://ublockorigin.com/
https://signal.org/
@signalapp