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 provides a photo-realistic simulation of a rare 1974 financial calculator, offering full functionality for loan amortization, saving plans, and depreciation. It features an authentic design with animated keys and an optional live register view.
- Photo-realistic design
- Live register view
- Animated keys with sound
- Full HP-70 function implementation
- Cut/copy/paste display value
- Built-in manual with examples
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RPN-70 HD is a complete, photo-realistic simulation of the financial hand-held calculator HP-70 from 1974. It handles loan amortization, saving plans, depreciation, and much more with ease. What users said: "Hard to find a decent calculator on iPad, try this one." "I don't normally write reviews but RPN-70 is just too fantastic to not get excited about. Apple should list this app under their Education category in the App Store and make it a must have for every college bound student. It is the best HP emulator in the market." "An incredibly well-engineered calculator app, and free, to boot!" "This is a really cool Financial calculator. Just like using the original HP-70. Accurate to the penny." Features: • Photo-realistic look based on an existing device • "Live" register view in landscape mode • Animated keys with click sound (adjustable volume) • All functions and operations of the HP-70 fully implemented • Simulation of the HP-70's computation time (optional) • Correct wrong number entries by swiping left across the display • Cut/copy/paste of display value • Visual indicators keep track of stored input parameters (optional) • Stack shown right below display (optional) • 10 non-volatile memory registers (optional) • Built-in short manual with many examples The HP-70 was discontinued after just one year. It is one of the rarest calculators, hard to find in any condition. NOTE: RPN-70 HD is a faithful simulation of a vintage HP-70 calculator, as has been verified against a real device using the examples in the Applications Cookbook section of the HP-70 manual. In certain cases, what may appear like a bug of the app is actually an idiosyncrasy of the HP-70. IMPORTANT: The HP-70 requires exactly three input parameters from the top-row keys, at least one of them being either "n" or "i". In other words, you can't use PMT, PV, and FV as input parameters simultaneously. A version for the iPhone named "RPN-70 SD" is also available. Visit the website: www.cuveesoft.ch
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
RPN and WP 31s both sit at 5.0 stars, but that hides the real split: 100% of WP 31s's written reviews are positive against 83% of RPN's. WP 31s also leads on ratings volume (15 vs 3) and device support (3 vs 1). On price, rating, update cadence and ads 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.
On the App Store both sit at effectively the same score — 5.0 for RPN against 4.9 for WP 31s. 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 are what separate them: 83% of RPN's written reviews are positive against 100% of WP 31s's.
RPN ships an update every 9 months, WP 31s every 10 months. The most recent releases landed on November 4, 2026 and November 2, 2026 respectively.
| Parameter | RPN | WP 31s |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (3 ratings) — better | 4.9 (15 ratings) |
| Positive reviews | 83.3% of reviews | 100.0% of reviews — better |
| Number of ratings | 3 | 15 — better |
| Update frequency | Every 9 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 | 14 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
