I used it for Calc 1 and 2. It helped me check my work for Limits, derivatives, integrals, Reimann Summs, Series, Sequences. I love the part that says "Show Step By Step" because I can figure out which step I made an error.
The answers in the back of the book didn't tell me step-by-step how I solved the problem. It just gave me the answer and there are many times I couldn't figure out which step I made the error. Usually it was some dumb mistake, but by identifying the dumb mistake, I could remember to double check that similar step in future problems.
I had a hard time using it for Classical Physics to check my work.
Having someone, or a program, show you where you went wrong is a good way to learn nothing. All the learning comes with struggling when you almost have the answer.
The answers in the back of the book didn't tell me step-by-step how I solved the problem. It just gave me the answer and there are many times I couldn't figure out which step I made the error. Usually it was some dumb mistake, but by identifying the dumb mistake, I could remember to double check that similar step in future problems.
I had a hard time using it for Classical Physics to check my work.