What is the use case for this? It's hard for me to see anything other than K-12 math homework (or early college, in some cases). Even graphing calculators have broader applicability than that, and that's saying something.
I'm tempted to go one step further and say that it's hard to see it as much more than a "do my homework for me" app, but I know that's too harsh. Some wise users might turn to it only to check their answers, or to get a hint about the next step if they're stuck. But as a professor, I've seen just how easy it can be for even strong students to come to over-rely on "Help, I'm stuck!" opportunities if they're available, and that doesn't assist with learning. (In one memorable case, that opportunity was me in my office, and I eventually had to limit my supply of helpful hints.)
I will admit, as a once ardent anti-math student, I appreciate how frustrating it is to sit down, stare at a problem for 10 minutes and advance no where through feeble attempts.
When I began taking Calc 2 (as an adult who's worked and gone back to school), I found wolfram alpha's integral solver to be INCREDIBLY helpful for working through practice problems (to your point, I was using it as a check/next step assistance). I ended up with an A in that class because of Wolfram's ability to help me work through a problem regardless of the hour, or day.
I think if this (or a similar app) helps students work through problems and recognize errors they're making, it can absolutely be beneficial. I would concede with respect to the homework solver aspect, but hope that teachers could some how incorporate this into their classes, something along the lines of an account management system that shows the teachers which students are requesting which equation.
It seems like a failure of the course/teacher if you are asked to solve a problem in which you can't identify the requisite steps and make progress?
In my mind the reason for problems is to practice the techniques taught until you can:
a) avoid common pitfalls
b) recognise common patterns
c) minimise calculation errors with sense checks
However, when this problem set is marked and impacts your results obviously the incentives change from learning by doing to getting 100%. Once you have an app like this for "checking", it takes decent appreciation of the long term outcomes to avoid using it for "solving" and then going off to play some Frog Fractions.
Some problems have several steps or techniques that need to be applied. It's not always obvious which way to go at first. Near the end of a course, or in higher-level courses, there could be hundreds of possible "next steps" that you've learned. Recognizing common patterns doesn't help in uncommon cases.
Sure, but that doesn't mean a tool to help when the course/teacher isn't fantastic isn't a good thing. It's an easy thing to abuse, though, and I think self restraint with regards to just googling answers is becoming an important study skill.
Applications like this are BEST used when utilized as yet another "tool" in the proverbial toolbox, and NOT as an endgame(ie: not a problem solver).
I too used WA to great benefit when taking the full calc series at my university and I credit it to helping me achieve straight A+'s in the series(the ONLY A+'s I EVER received in Uni). Yes, I studied my butt off too, and looked at outside work to learn the material, but WA helped ensure I was on the right track, or at least gave me "hints" as to what I was doing wrong. I never once used it as a solution, merely a calibration of my methods.
So yes, I think there are definite places for tools like these in the classroom, as much as it may seem like they are "cheats".
I'm tempted to go one step further and say that it's hard to see it as much more than a "do my homework for me" app, but I know that's too harsh. Some wise users might turn to it only to check their answers, or to get a hint about the next step if they're stuck. But as a professor, I've seen just how easy it can be for even strong students to come to over-rely on "Help, I'm stuck!" opportunities if they're available, and that doesn't assist with learning. (In one memorable case, that opportunity was me in my office, and I eventually had to limit my supply of helpful hints.)