I’m not a Wolfram|Alpha Pro subscriber, but I might become one to play with this
This is a tutor disguised as a problem generator. It’s just for math, and simple branches of math, at the moment. There are 6 groups listed: Arithmetic, Number Theory, Algebra, Calculus, Linear Algebra and Statistics, and it’s all pretty basic portions of those groups.
The point of this? You get custom-generated problems, and it gives you applicable hints if you get stuck at any step (the tutor part).
What the world needs, of course, is something like this for programming.