What is the the most educational software for high school and college math?
Not the one that just gives you the answer, but has
any of the following:
Edit: Software mentioned in answer added in brackets
- provides step-by-step solutions [WolframAlpha];
- can verify your step-by-step solution [empty];
- can give you hints [empty];
- can generate problems similar to given one [empty];
or something along those lines.