Comb is an Emacs tool for exploring projects with regexps: https://github.com/cyrus-and/comb/blob/master/README.md
The UI looks very polished!
Related Posts
Today I learnt that Emacs 28 shipped a context-menu-mode! https://oylenshpeegul.gitlab.io/blog/posts/20230129/
This seems quintessentially Emacs: deeply hackable, but building UI features in an order very different to the mainstream.
For hobby projects, I really like software where I can do small features or tweaks. Sometimes I don't have time for anything more substantial.
Website projects are great for this. Are there other areas?
Exploring design ideas using AI as a learning assistant, for creative exploration: https://andymatuschak.org/hmwl/