What's your function?

This graphing calculator application has an easy to use interface with its sizeable buttons, customizable background colors, and clear grid lines. However, it can be overwhelming at first, since there's no tutorial or built-in help available.

Variables, constants, math, and trigonometry functions and symbols are categorized into their own corresponding sections. Touch the appropriate button at the top of the calculator interface to cycle through and add to your equation without the frustration of having to type them all out.

Adding functions to the graph is fairly simple; enter a function, select the resolution, and the minimum and maximum exponents. The graph comes out instantly, with no strain on the iPhone or iPod touch. The calculator has more than 25 built-in functions and can store results into custom variables for complicated equations.

Unfortunately, the interface gave us difficulty when interpreting coordinates because the graph only counts by 10s, unless you zoom in. But, if done incorrectly, pinching will increase or decrease coordinate values, rather than zooming in and out of the graph.