"Introducing App Tracking Protection for Android: The easiest way to block trackers lurking in your apps" https://spreadprivacy.com/introducing-app-tracking-protection/

This sounds like a really clever implementation ("local VPN"). I've been waiting for something like this for Android, but none of the existing solutions (even the ones that merely report which apps are phoning home to where) seemed to work very well. I'll be curious to try this out when it ships.