The little things
Some of my favorite PCalc features are the little touches. For example, the app automatically scales text size as more numbers appear on the display, so when you're doing simple one-line calculations, you see bigger numbers. There's a dedicated frac key for entering fractions — tapping 3 frac 7 enters 3/7. (You can also double-tap the . key to perform the same action.) You can disable auto-lock, so your iPhone or iPad stays awake while you're using PCalc, and an Accounting mode automatically adds a decimal point and rounds numbers to two decimal places. When in algebraic (non-RPN) mode, you can repeat the last calculation by simply pressing the = button again.
A nifty feature added in version 2.7 is a "ticker tape" history banner just below the main display — the type is small, but a quick swipe lets you browse your recent calculations. You can also enable key popovers that function much like the ones you see on iOS's standard keyboard — when you tap a key, a larger version of it appears until you release it. (This feature is especially handy for increasing accuracy on the iPhone's smaller keys.) I also like the option to display a blinking editing cursor in the display, so you know whether a number is one you're still entering or the result of a calculation.
Smartphones and tablets don't give you the tactile feel of a hardware calculator, but they allow app developers to create the perfect calculator — whatever that might be for a particular individual. For example, you can choose a natural-language calculator such as Soulver, or even one like MyScript that lets you write your equations right on the screen. In the case of PCalc, TLA Systems has designed the ultimate scientific calculator: one that's fantastic today, but that's also regularly updated with new features, functions, and faces.
When I reviewed PCalc 2, I was impressed that the developer had squeezed so much into the program without making it unwieldy. PCalc has since gained even more features, and yet it's just as easy to use as before — in some ways easier, thanks to interface improvements. Whether you're performing serious scientific calculations, doing high-school physics homework, or just converting everyday measures, PCalc has the features and interface for you. And if you want to try before you buy, you can download the free Lite version and then pay for just the features you need, when you need them.
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