Share on Twitter
Automatically share WordPress posts on Twitter. You choose which Post Types are shared. (Sharing can still be disabled on a per-post basis.)
This plugin shares a lot of code with Share on Mastodon and Share on Pixelfed and functions in much the same way.
It does not, however, automatically register itself as a Twitter client when it is first set up: in order to Tweet from your WordPress instance, you will therefore have to sign up as a developer first, and register a new app with read and write access. Only then will you be given a set of API secrets that allow WordPress to post on your behalf.
While this is tedious, it’s also the only way. Twitter asks client API keys are kept private, which I interpret as: can’t be shipped as part of an open-source application. (I also suspect this to be the reason a plugin like Jetpack, which offers a similar service, requires you connect to the WordPress.com servers for you to post on Twitter.)