I’m not aware of any service that [goes fully peer-to-peer] while being practical for most people, yet.

Retroshare is almost ready for prime time after remaining in development for over 20 years. Each “friend” runs it’s own service for the decentralized network of “friends” and hands off message fragments from immediate “friends” for swapping files, store-and-forward messages, chats, etc., to other more distant network participants.

The swindle is that your friends know you by your IP address. If Big Government, Big Media, or Big Crime knocks over one of them, they’ve got you, too. But — not to worry — you can actually — so I’m told — run an RS instance behind a TOR hidden service.

I much prefer the article from 22 Mar 2019 about “TOR Onion Services” preserved at the Wayback Machine instead of the current article.

I have a little python script that (among other things) will maintain an address list in a *.csv file on a Windows or Linux PC. It’s a Qt app. The documentation does some handwaving about importing/exporting to Android. See: https://lacusveris.com/Tonto2/Docs/en/index.shtml