[Amazonerh]

This is really groundbreaking but it got less noise than I thought it would. Adhell (an app that is capable of doing system wide ad blocking along with many other things thanks to Knox which is Samsung-only capability) was the main reason I stayed with Samsung for years. Now every phone with Android Pie will be to use dns based ad blocking in all networks without running an annoying app in the background.

[Nullabillity]

There's also AdAway, which runs on any rooted Android phone, and doesn't require you to show all your traffic to a particular DNS server.

[cyberpip]

There is also Blokada, which creates a local VPN on Android and runs it against a hosts file: https://f-droid.org/en/packages/org.blokada.alarm/ .

[jsmith99]

The advantage of Knox based blocking is that it doesn't require root.