I've used a JS-to-SVG flowchart generator to help illustrate JS logic outside of JS grammar: bogdan-lyashenko.github.io/js-code-to-svg-flowcha…
I'm also curious about other tools here - I've got a number of similar plugins that share a lot of code, and I've been looking for insights on how the common parts of those plugins might be merged, or how to better separate all the boilerplate that's in all plugins from the bits that are unique to each :D