RePNCalc 2

Crunch your numbers with the rpn calculator that fits right along side every other iOS app! Don't get held back by the conventions of traditional, keyboarded calculators that can't update their buttons with new functions without the use of a shift key! Use technology from the future, like swipe gestures to change key layouts or touching and holding a stack item to get a popup granting a range of options.
This calculator app uses the alternative method called "reverse polish notation" to provide input for calculations. For the curious, check out http://en.wikipedia.org/wiki/Reverse_Polish_notation for more information.
You can now also use external keyboards for input, not just the buttons on screen.
Purchasing the full version (in the app) unlocks full functionality. Included is basic functionality (+, -, x, and ÷) and complete support for iPad, iPhone, and iPod touch.