JSCalculator is a scientific calculator app that provides editable formulas, storage of preferred formulas, and predefined constants of nature. This is not an imitation of a limited stand alone electronic calculator of old. This is a calculator that exploits the power of the device it is running on. It works slightly differently, but it allows for more flexibility. As an example, JSCalculator evaluates what you type without the need of hitting "=" or an enter key. In this calculator, the "=" key is for assigning values to variables, not for telling it to execute a calculation!