I just discovered this and it works fantastically on any old / unused android device you might have lying around, I was shocked at how easy it was, all the instructions are there, once you have it running all you need to do is set your router DNS settings to your pihole IP address and presto! Ads and trackers are gone!
The FP3 requires a battery at least. Ironically the device will actually still turn on and be usable if you removed ALL the modules besides the display module 😅 and of course the mandatory battery