Twitter doesn't let you edit one of your posts. You can buy an edit button that works for a few seconds, though.

Mastodon (or at least GlitchSoc) sort of lets you edit one of your posts, via a "delete and redraft" option.

#HiveSocial lets you edit your posts. And anyone else's posts. Among other nasty things. https://zerforschung.org/posts/hive-en/

While it'd be nice to dress up the bug & call it a feature ​, it's why they're unplugging the servers to fix it instead.