I'm not part of the Dev team, but I do donate to the patreon because I'd love it to succeed.
Mastodon is a FOSS alternative to Twitter, with a focus on UX. Github: https://github.com/Gargron/mastodon/ Screenshot and demo video linked from the README
Sorry to be pedantic, but it's implementing OStatus standard.
I'm not part of the Dev team, but I do donate to the patreon because I'd love it to succeed.