AdAway is an open source ad blocker for Android using the hosts file.
Google Play Store notice:
According the Google Play Developer Policy, especially the "Device and Network Abuse" section, ad blocker like AdAway violates the "Apps that block or interfere with another app displaying ads." rule and can't be distributed on distributed on the Play Store.
This application requires Android 8 or above and does no more require root.
For older Android versions, a rooted device is required.