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. New variables and functions may be defined by the user.
Moreover, functions f(x) of one variable can be plotted, and functions f(x,y) of two variables can be visualised in a grayscale "map". Parametric plots, where x and y coordinates are determined by a pair of single-parameter functions, are also supported.