R47 Zen RPN Calculator

R47 Zen is a programmable RPN scientific calculator for Android. It runs the R47 variant of the open-source C47 calculator core: 34-digit decimal arithmetic and more than 1,500 operations, on a keypad laid out like the R47. If you know the HP-42S or the WP 34S, the RPN way of working will feel familiar, though many menus and keys are new.

What you can do
- Work in RPN on a 4- or 8-level stack with real, complex, integer, fraction, date, time, text, matrix and vector values
- Use a large scientific catalog: trigonometric and hyperbolic functions, logarithms, gamma, Bessel functions, prime factorisation and more
- Run statistics with nine best-fit models and 17 probability distributions
- Solve equations, integrate, differentiate and plot functions
- Compute in binary, octal, hexadecimal or any base from 2 to 16, with word sizes up to 64 bits
- Convert units and use 83 built-in physical and mathematical constants
- Do date and time arithmetic and time value of money calculations
- Write keystroke programs with tests, loops, flags and local registers
- Customise the keyboard and soft-key menus in USER mode

Made for Android
- Your last session comes back when you reopen the app
- Open and save states, programs and display screenshots with the Android file picker, or choose one Work Directory
- Copy registers to the clipboard and paste numbers into the calculator
- Four LCD color themes, a negative display and full-screen mode
- Drag and pinch on graph screens
- Keypad labels that follow the active shift and mode, or stay fixed
- Haptic key feedback and an optional simulated beeper

Private by design
R47 Zen has no ads, no in-app purchases, no accounts and no tracking. It does not request the Internet permission, so it works fully offline and cannot send your data anywhere. Privacy policy: https://ppigazzini.github.io/r47zen/privacy-policy.html

Open source
R47 Zen is free software under the GNU General Public License, version 3. The source code is at https://github.com/ppigazzini/r47zen. The calculator core comes from the C47 project. R47 Zen is an independent app: it is not an official release of the C47 project, and it is not made by or affiliated with SwissMicros, which builds the R47 hardware calculator.

Help
Report a bug or ask a question by opening an issue on GitHub. The R47 manual and function catalog at 47calc.com describe every function.