I don’t know about graphene, but doesn’t some android roms allow to use custom ( more private Webview implementations) instead of default ?

Used nostr without much idea about itself, but using Amethyst, it was the easiest i ever created account ever in my life

The working involves relays ( which reminded me of tor ) which helps messages pass from you to others and from them to you.

Discovering accounts can be through their public key or as usual, their username ( if set ). Its usable with just the key generated during our signup.

The downside is not much active communities and users other than mainly crypto enthusiasts, but people are increasing.