I love this; Hewlett-Packard is selling an exact copy of its HP-12C financial calculator for the iPhone.
The iPhone version of the HP-12C is a near carbon copy of the actual machine. It not only looks the same, but it actually runs the same code as do the physical calculators. The iPhone version is actually a bit better than just a clone of the original, though, because HP includes a simplified portrait-mode calculator (the 12C is a landscape-mode device). When used in portrait mode, you can use the number keys, along with all the usual math operators and a couple of other functions such as square roots and memory—perfect for those times when you just need a basic calculator.
The real power of the HP-12C is found when you rotate your iPhone to landscape mode; what appears on the screen then is a photographic reproduction of the actual HP-12C calculator, complete with the gold-brown-orange-blue color scheme that made the original so…endearing? Because the app uses the actual calculator’s code, absolutely everything works just like it does on the real calculator.
I used a calculator just like this to win a middle school mathematics competition – in those days, it was called a “Calculator Competition,” because you could (gasp!) use a calculator. There was a school-wide thing, then a regional, and then a state final; it was a whole thing. The state final was the first time I’d ever seen a graphing calculator; that shiz blew my mind.