Basic but good
+• RPN logic +• Scrollable history +• Apparently unlimited stack* [The three points above help lead to a quick understanding of the basics and advantages of Reverse Polish Notation (RPN)] +• High precision +• Decimal to fraction conversion with a single tap of the mode button +• Clear uncluttered appearance ++• Zero advertising or other interfering garbage -• No scientific functionality -• No landscape view Used in portrait orientation, this is a punchy little app; but an iPad sitting horizontally on a desk means learning to read sideways… *The stack is a list of entries and results. At the bottom of the stack the X registry contains the latest entry or result; and above it, the Y registry contains the previous entry or result. This app has an X<>Y key allowing the two to be swapped. Thus, a previous result can be re-used without re-typing and re-entering it. Handy!
