XPrivacyLua is no longer maintained YFI. It still seems to work just fine for now, but that probably won’t last. I’ve not found a good replacement for it yet.

I keep my keys on a Yubikey. I’ve not really had a need to use the GPG portion of this on Android, but it works fine on Linux and MacOS.

I used this guide: https://github.com/drduh/YubiKey-Guide

They would show for others on your instance, but not for people on other instances, so each instance will have a separate downvote counter.