This is awesome. Congrats on shipping!

The nearest thing that I've heard of is Wolfram Alpha's step-by-step solution solvers, but the worry with those is always that it's too easy for the student to just keep clicking next step and not learn anything.

I appreciate how this frames algebra as a puzzle instead of a problem :)

The Wolfram thing: https://www.wolframalpha.com/examples/pro-features/step-by-s...

Specifically this one: https://www.wolframalpha.com/input?i=find+t+for+t%5E2+%2B+3t...