Pocket ESP (Equation Solver Program) 1.0

the author of this app says:

PocketESP (Pocket Equation Solver Program) allows you to enter equations and solve for any variable in the equation.

The applications are virtually unlimited: business, engineering, finance, medicine and more. And variable values are global, meaning the values are preserved from one equation to another. This allows equations to be linked into sets to solve complex problems.

Each equation can contain up to 16 variables, and all standard functions are supported (log, ln, cos, acos, cosh, exp).

Equations can have reference values (named numeric constants) and they are displayed when the equation is displayed.

Solver can store any number of equations in a file, and you can have any number of files (limited only by memory).