Causal loops is created by  Brainpartner

The app is FREE and will stay free. To make this possible, you will see some advertisements. If you do not want to see the advertisements, you can use an adblocker. If you do, I appreciate a small donation.

The original source is   Loopy from  Nicky Case
LOOPY is part of  EXPLORABLE EXPLANATIONS a movement that actively stimulates learning.  LOOPY is open source and public domain. This means that it is free for programmers, teachers and anyone else who can reuse and modify LOOPY as they see fit.