As a current math student, and future math teacher, I have been looking for a website or app that might help me solve more advanced problems. I think that I have found it in mathway.com this helps you find out the answers to basic math, algebra, trigonometry, and even calculus and statistics! All you have to do, is tell the site what type of math you are doing and type in the equation that you are trying to solve. Then, just hit solve and it give you the answer. Now, you do have to pay to view the how to solve portion of the problem, but this site can serve as a fancy calculator for free.
Since mathway is a website, it can be accessed by any computer or smartphone with internet access, but there is also a mathway app in the iPhone and Android markets. The app works exactly the same way as the site, only mobile.
I can see using this on a limited basis in the classroom, letting students know that it exists, but advise them only to use it to check their answers. Either way, mathway is a solid site and app to help solve math problems.