Javia Calculator - easy-to-use calculator for mobile phones. It features a user interface designed for the mobile phone's keypad, which allows quick input of mathematical expressions.
Built-in functions include trigonometric and hyperbolic functions, logarithms and exponentiation, permutations, combinations and factorial
The program TouchMaths (for touchscreen mobile phones) contain a set of revolutionary mathematical applications (Professional Calculator, Graph 2D, Function solver, Integral solver, Equation solver and Linear system solver)
Frink - Frink is a programming language and calculating tool designed to help you make real-world calculations.
Frink is different than other calculating tools in that it tracks units of measure through all calculations. Thus, you can add feet and meters, multiply by grams, divide by pounds, and Frink does the right thing through all calculations