I always wanted to love ProGraph - I played with it back in the pre-OSX Mac days. But I found it's very hard to "read" ProGraph code, which it would seem is the thing that visual languages are supposed to enable. It could be that my brain had already been shaped into text based programming for too long to adapt.
That said, I did create a visual toy language demo a few years back for the fun of it. It's kinda like a visual Lisp, or maybe upside-down ProGraph: https://github.com/mypalmike/skastic
https://en.m.wikipedia.org/wiki/Prograph