For anyone else who would prefer a local editor, my understanding (after a brief search) is that this is a browser version of https://drakon-editor.sourceforge.

For anyone else who would prefer a local editor, my understanding (after a brief search) is that this is a browser version of https://drakon-editor.sourceforge.net/ https://drakon-editor.sourceforge.net/. I found it in the AUR on arch. Elsewhere on windows/mac/linux. I'm not sure if I'll ever use this as an alternative to writing code, but I like the pretty diagrams.