RPN vs WP 31s
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
RPN
This app simulates a legendary vintage scientific calculator, offering a "live" display of its internal states and a virtual paper tape printer. It allows loading and running original sample programs, with advanced features that can be switched off for an authentic experience.
- Live display of stack and registers
- Virtual paper tape printer
- Email or print paper tape
- Cut/copy/paste display value
- 30 selectable background images
- Non-volatile memory
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RPN-67 NP is the non-programmable version of RPN-67 Pro, the first complete simulation of Hewlett-Packard's HP-67 legendary programmable calculator for iOS. Produced from 1976 to 1982, the HP-67's capability to store programs on magnetic cards, wide array of functions, merged keycodes, indirect addressing and other enhancements made it a huge success among scientists, engineers and other professionals. Thousands of programs were written for it. RPN-67 NP allows you to load and run 25 original HP sample program cards. It lacks the program creation and card management features of the Pro version, as well as its massively expanded array of functions and operations. Apart from these restrictions, RPN-67 NP is a very capable vintage scientific calculator. Features: • "Live" display of stack, memory registers, program counter, flags • Virtual paper tape printer • E-mail or print the paper tape • Cut/copy/paste display value • 30 selectable background images, even add your own. More features the HP-67 never offered: • Non-volatile memory - stack, registers, program • Status indicators for prefix keys (f, g, h, STO, RCL, GTO, DSP) • Keycode-to-command translation while single-stepping a program • Cancel SST or BST operation by sliding your finger off the depressed key All advanced features may switched off with a single setting, allowing you to experience a real HP-67 as closely as possible. For more information visit the RPN-67 website: cuveesoft.ch/rpn67
WP 31s
This app emulates a classic RPN scientific calculator, offering a rich function set for daily use with a simplified interface. It's based on the more complex WP 34s but is designed for easier operation.
- RPN scientific calculator emulation
- Rich function set
- Simplified, less cluttered keyboard
- Based on WP 34s
- Available on iOS
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WP 31s is a classic RPN scientific calculator based on the powerful but more complex WP 34s. Now available on iOS too (see the support site for other emulators and for the real stuff). It is not programmable but has a rich function set for daily use and is easier to use, thanks to a less cluttered keyboard. A manual can be downloaded at http://sourceforge.net/projects/wp34s/files/doc/Manual_wp_31s_1_2q.pdf/download
Screenshots
Verdict
The clearest difference is rating: WP 31s at 4.9 against RPN's 3.7. WP 31s also leads on review sentiment (100% vs 83%) and ratings volume (15 vs 3). RPN's advantage is update cadence (every 5 months vs every 10 months). On price, ads, in-app purchases and monetization model there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
WP 31s holds the better App Store score, 4.9 against 3.7. That said, the two scores are not equally well evidenced: WP 31s has 15 ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 83% of RPN's written reviews are positive against 100% of WP 31s's.
RPN ships an update every 5 months, WP 31s every 10 months. The most recent releases landed on September 21, 2026 and June 11, 2026 respectively.
| Parameter | RPN | WP 31s |
|---|---|---|
| Price | Free | Free |
| Rating | 3.7 (3 ratings) | 4.9 (15 ratings) — better |
| Positive reviews | 83.3% of reviews | 100.0% of reviews — better |
| Number of ratings | 3 | 15 — better |
| Update frequency | Every 5 months — better | Every 10 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPad | iPhone, iPad, iPod — better |
| Requires iOS | 12.0 | 12.0 |
| Further details — not scored | ||
| Size | 38 MB | 16 MB |
| Age rating | 4+ | 4+ |
| Developer | CuVee Software | Pascal Meheut |
Customer experience
RPN
WP 31s
In-app purchases
RPN
No in-app purchases
WP 31s
No in-app purchases





