This RPN calculator takes full advantage of the new Full Screen Mode in Lion. And when you're not using the calculator in full screen mode, the window is fully resizable. The RPN behavior in this app is based on classic HP calculators. All the essential functions for everyday calculation are included. All memory registers are saved when you quit the app.
"All the essential functions"? "Based on HP calculators?" Ummm…say what?? While I guess it's true that this is, indeed, a calculator that uses Reverse Polish Notation, IT IS A FOUR FUNCTION CALCULATOR! Who on earth needs RPN to add and subtract numbers? As far as I can tell, not only doesn't this have functions (forget "advanced" functions), it doesn't even have a stack(!), which makes it useless for serious calculations. If you are reading this review, you're probably in the market for something reminiscent of an HP12c calculator. I'm afraid, however, that this isn't it.