Does Pavlok 3 work with Android phones as well with iPhones? Does it work with tablets?

Absolutely, there’s a Pavlok app both for Android and iOS.
You can use Pavlok with an iPad or most Android tablets.

LIST OF CONFIRMED INCOMPATIBLE PHONES

We’ve found that Samsung Galaxy A10 phones and A-series tablets don’t support Pavlok (as they don’t have adequate Bluetooth low energy support).
Other Galaxy devices may be ok

Samsung J-3 2018 version

POSSIBLY:
J7 though it is more than 3 years old I don't think it's going to be much of an issue in the future
A7 from 2018