RPN is a slightly unusual four function calculator for Android. It’s designed to replace the standard built-in calculator, and features large buttons designed for easy touchscreen use.
It has three unusual features:
- It uses Reverse Polish Notation, as commonly found on HP calculators.
- It uses decimal arithmetic.
- It uses fixed point.
- It does not offer scientific functions, unit conversions, base conversions, programmability, memory registers, or any other advanced functionality, because I don’t need those things when I’m away from my desk, and I wrote the program to “scratch my itch”. If you need that stuff, there are at least half a dozen scientific calculators available for free in the Android Market, including an HP48 emulator.
If you just want to install the calculator, you can do that easily; see RPN on the Android Market.
If you want to read more about why I wrote this calculator, and why it's the way it is, my web site has details.
Source code licensed under the GNU Public License, Version 3 or later. Improvements are welcome.
- Fixes visual glitches on Jelly Bean (Android 4.1) on Galaxy Nexus.
- Fixes double audio feedback on keyboard buttons.
- Improves haptic feedback to fire when the key is touched, like the regular on-screen QWERTY keyboard.
- Now requires Android 4 -- use 1.x (commit 199a87f731) if you are stuck with an earlier OS version.
- Completely reworked Android 4 UI, with Roboto font.
- Now requires at least 320x480 resolution. As far as I know there aren't any Android 4 devices with a lower resolution than that; in fact, the SDK Android 4 image copes badly with a display that small.
- Now runs in portrait only. I found that orientation changes were more annoying than anything else, and there just isn't enough space for 4 rows of usable keys, plus an action bar, plus a number display with at least two lines.
- New square root button, as per user request.
- Single keypad (no shift), a benefit of going portrait mode only.
- Improved key labels for special functions.
- High resolution icon.
- Significant code cleanup thanks to Android 4 APIs.