This is a fully functional, scientific, Reverse Polish Notation (RPN) calculator. It has basic, scientific and user configurable layouts. Numbers are displayed in user configurable fixed, scientific and engineering formats. It has 73 built-in functions covering: logarithms, powers, roots, trigonometric, date, time, memory operations, statistics and probabilities. In the user configurable layout there are 16 user configurable function buttons. Numbers can be copied to and pasted from the clipboard for ease of use with other applications. It includes an operation history display for ease of reviewing calculations. User defined macros can be configured, executed, and assigned to user configurable function buttons. It includes extensive in-app help documentation.