I recommend adding a setting to customize where the buttons are on the calculator, well worth the $10/month, it's really good but it just needs slightly better camera software then it would be perfect. Go download the app because its easy to use and its really useful :). Only thing is you shouldn't use it on its own as some if the ways they get answers are on the complex side and if you are here that's probs too much, best used as a supplement to check work and give you hints.
But this app helps me a lot, i'm a first time college student at the age of 40 and going for a engineering transfer degree. I struggle with math and now I have a way to understand the problems, the only problem is it does not fully solve equations that involve imaginary numbers.