Thank you! I actually can’t remember what made me start building it. I think I was learning differential equations and wanted to try visualizing some parts of that, and it spiraled into a full blown thing. I kept getting impressed by the flexibility and accessibility of SVG.
I don’t really have a target audience, I just enjoy building it. As I add more examples I expose more weak spots or feature opportunities.
Regarding your SO, Mafs could be a good fit if she knows React, but if not, Geogebra is a fantastic WYSIWYG visualization editor. Mafs would have the cool benefit of being able to show the underlying logic to the student though :)