I agree that the project is cool. But I just want to give the answer that always aught to be given whenever someone on HN says "I wish we had X when I was learning this stuff", where X usually is some visual way of illustrating a concept. And that is simply that there really isn't any good substitute to learning mathematics to simply doing a bunch of problems with good old dry symbols. Visualizations are great, and they can aid intuition. But that is not the be all and end all. Struggle and doing a large number of problems really is necessary in order to internalize this stuff to such a degree that you maintain a deep understanding ten years after you were first exposed to it.