PrettyPrint Calculator is a great an app that displays the equations you enter in a nice looking format, with fractions, exponents, and radicals. The interface is very intuitive; enter your equation as would normally do, and PrettyPrint Calculator does all the heavy-lifting in the background to produce intuitive looking equations. Whats more, you can keep a history of your last entered equations for easy reference.
Optimized for the Retina Screen and iOS 7, enjoy a truly gorgeous interface without clutter, and an intuitive way to perform calculations on this platform.