The best math app in my opinion is
Wolf ram alpha.
Just place your equation in the box (e.g. [3^3]/5) And it will give you an answer such as this
link.
Take note I used to use this when in High School, so I know its extremely effective on getting the correct answer but not much else...
A web site I have fallen in love with is call Khan Academy... This website EXCELS at showing you step by step problem solving...
Here is a video to show you what they are like.<font size="3">[video=youtube;Gn2pdkvdbGQ]https://www.youtube.com/watch?v=Gn2pdkvdbGQ[/video]
(take in note he has gotten better at his presentation throughout the years, this video is from 2007)