Firefox iOS has a "Tracking Protection" feature which will block ads that do more aggressive tracking. It's on by default but I recommend toggling it onto stric

Firefox iOS has a "Tracking Protection" feature which will block ads that do more aggressive tracking. It's on by default but I recommend toggling it onto strict mode for best results. You can also use Firefox Focus to apply the same functionality to the default Safari browser. The thing with the most potential on iOS is Lockdown, a local-only firewall which filters network connections from any application. It'll break apps like Facebook Messenger if you turn on all the options. But again, it's focused on trackers, not ads specifically.