I wrote my own email service: https://port87.com/

I’ve made a lot of things for it, and most of them are open source:

• https://sveltematerialui.com/
• https://hub.docker.com/r/sciactive/nephele
• https://nymph.io/
• https://github.com/sciactive/tokenizer

Also, I made one of those neat sorting algorithm visualizers:

https://sciactive.github.io/libsortjs/demo/