iRPN is a free Reverse Polish Notation Calculator app.
In Reverse Polish Notation operators follow their operands, for example: 1 + 2 would become 1 2 + in Reverse Polish Notation. In order for this to occur, numbers are pushed onto a stack and popped as the user applies operators. A benefit of Reverse Polish Notation calculators is that they don’t require parentheses as opposed to typical, infix calculators.
Features:
-Ability to re-order numbers in the stack
-Selecting a cell in the stack displays how you arrived at the result
-Access to scientific expressions in landscape mode
Developed by Joseph Arreola, from the Proviso Math and Science academy high-school, during his research mentorship at Bits labs.