Here: https://fxdreema.com/studio/
Not many people are using it, I also rewrote this thing as well and what was written for it before is not very accurate now. But if it works, you can create a new block (upper left), then write some code for it, save it and use it. Optionally input parameters can be defined for this block.
Here is how it looks for me now, if it helps: http://prntscr.com/8emuzf
~next~ ~inext~ and ~error~ are the keywords behind the 3 possible outputs (orange, yellow and gray) and they are replaced with function calls for the next blocks connected to this one.