To mathematics students and enthusiasts who are looking for a free calculator app, you might want to look at the Good Grapher App. The Good Grapher app is an excellent grapher with lots of features. It can be used from elementary school up to graduate school. It is available as iPhone and iPad apps.

Below are only some of its amazing features.

- supports real and complex numbers
- has astronomical, atomic, electromagnetic, mathematical, physicochemical, universal constants
- modular and factorial operations
- assignment operators for storing values
- 2d and 3d graphs with customizable colors and table of values
- multi-touch support
- contains math solver (solving equations)

*Note: I am not receiving any compensation in reviewing software. I write about them because I personally like them and believe that they can be of help to others.*