I began contributing to the development of footnotes, a popular WordPress Plugin with over 7,000 installations, after posting a bug report on the Support Forum.
My main contributions were to set up a proper development workflow including automated code linting and formatting, unit testing and standards compliance enforcement, as well as to move development away from SVN (pushing changes directly to the WordPress Plugin Directory repository) and onto Git (with development to take place on GitHub and the WordPress Plugin Direcotry to be used only as a release repository).
I also set about refactoring the 8-year-old codebase to produce a cleaner, more efficient Plugin which issues would be easier to diagnose and development would be more enjoyable. As part of this, I ported the codebase to PHP 8.0 and added automatic Rectorisation to the workflow to produce output that would be compatible with WordPress, whilst still allowing us access to the latest language features for development.
Unfortunately, the Plugin owner went out of contact and the Plugin is now abandoned, but I did my best to inform the userbase in a helpful way and I learnt a lot about development within the WordPress ecosystem from this project.