There’s Briar: https://briarproject.org/ and Manyverse which uses the Scuttlebutt Protocol: https://manyver.se which are close but not perfect. Source: about 1 year ago

Manyverse is cross-platform and it's the main desktop app nowadays: https://manyver.se The Scuttlebutt.nz website hasn't been kept up-to-date. SSB's development is also decentralized, so this doesn't mean that everything moves forward in unison, so depending on who you ask, Scuttlebutt.nz is not the official frontpage. - Source: Hacker News / over 1 year ago

Manyverse (version 0.2210.3-beta-fdroid): A social network off the grid. Source: over 1 year ago

This looks pretty interesting. Do you know how it is different from similar systems that use the SSB protocol, like Manyverse for example? Source: over 1 year ago

I really look forward to interfaces that let me use my own index of data from my network. Manyverse[1] and Iris[2] are good examples of apps that will enable this more in the future. I just want to search “harry potter” and see everything my friends have written about it. If I follow some institutions or encyclopedias, I should also see what they write about it. And I should be able to choose which... - Source: Hacker News / almost 2 years ago

No you don't...you just need a work email. cerner.com works. Source: almost 2 years ago