WP 34s vs RPN
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
WP 34s
This app is a powerful RPN scientific calculator with extensive functions for mathematics, statistics, programming, and engineering. It includes programmer functions, fraction mode, probability distributions, and a stopwatch, offering a comprehensive tool for complex calculations.
- RPN scientific calculator implementation
- Programmer functions (binary, octal, hexadecimal)
- Fraction mode and probability distributions
- Stopwatch with real-time clock
- Mathematical, statistical, and financial functions
- Unit conversions and physical constants
- Extended character sets for multiple languages
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WP 34s is the most powerful and complete implementation of a classic RPN scientific calculator. Now available on iOS too (see the support site for other emulators and for the real stuff). The function set of the WP 34S is based on the most powerful programmable RPN calculators built so far and we expanded the set, incorporating programmer functions (base 2, 8 & 16), a fraction mode, probability distributions, a stopwatch... We also included numerous additional useful functions for mathematics, statistics, physics, engineering, programming, I/O, etc., such as: + Euler’s Beta and Riemann’s Zeta functions, Bernoulli and Fibonacci numbers, Lambert’s W, the error function, and the Chebyshev, Hermite, Laguerre, and Legendre orthogonal polynomials (no more need to carry heavy printed tables), + many statistical distributions and their inverses: Poisson, Binomial, Geometric, Cauchy-Lorentz, Exponential, Logistic, Weibull, Lognormal, and Gaussian, + programmable sums and products, first and second derivatives, solving quadratic equations for real and complex roots, + testing for primality, + integer computing in fifteen bases from binary to hexadecimal, + extended date and time operations and a stopwatch3 based on a real-time clock, + financial operations such as mean rate of return and margin calculations, + 88 conversions, mainly from old Imperial to universal SI units and vice versa, + 50 fundamental physical constants as accurate as used today by national standards institutes such as NIST or PTB, plus a selection of important constants from mathematics, astronomy, and surveying, + Greek and extended Latin letters covering the languages of almost half of the world’s population (upper and lower case in two font sizes), plus mathematical symbols. A beginner manual can be downloaded at http://sourceforge.net/projects/wp34s/files/doc/WP_34S_Beg_Guide.pdf and a full, very complete version at http://sourceforge.net/projects/wp34s/files/doc/Manual_wp_34s_3_1.pdf
RPN
This app is a photo-realistic simulation of a classic Hewlett-Packard programmable scientific calculator from the 1970s. It includes a 100-hour digital timer, clock functions, and original HP programs.
- Photo-realistic look-and-feel
- Programmable with conditional branching
- 100-hr timer and 12/24-hr clock
- Original HP programs built-in
- Extended features for enhanced usability
- Sharing via email, AirDrop, and more
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RPN-55 SD is the first photo-realistic simulation for the iPhone of Hewlett-Packard's low-cost alternative to the famous HP-65 programmable scientific calculator. Produced from 1975 through 1977, it was the "Merlin" member of the classic HP calculator series, priced at $395. HP claimed that it featured "(...) more pre-programmed functions than any other scientific pocket calculator in the world." A main feature of the HP-55 was a crystal-controlled 100-hr digital timer with the ability to store times while the timer was running and later recall them. On RPN-55 SD the timer may also act as a 12-hr or 24-hr clock, including date and weekday display. While the simulator works just like the original calculator – except being much faster and having twice the program memory – you can turn on extended features to make it even more enjoyable to use. RPN-55 SD comes complete with original HP programs built in. Features: • Photo-realistic look-and-feel • Vintage mode or Extended mode • Programmable (99 steps), conditional branching • Insert and delete steps with automatic address correction • Delete range of steps • Subroutines (4 levels) • 20 registers, "continuous", with unrestricted store/recall arithmetic • "Live" register view • Program listing view • Program library view • Store and retrieve any number of programs • 100-hr timer supporting 10 split times and 12/24-hr clock mode with date • Swap unit conversions with additional functions, e.g. hyperbolics • Sharing: e-mail, AirDrop, Dropbox, copy, paste, print • 112 programs pre-installed Calculator functions: • Statistics (linear regression, mean, standard deviation, correlation coefficient, x- and y-estimates) • Trigonometric functions (degrees, radians, grads) • Polar/rectangular conversions • Inverse, square root, logarithm, exponential, pi • Storage arithmetic (store and recall) • Percent, absolute, integer, fractional value, round • Factorial • Random number • Unit and hours conversions Details: cuveesoft.ch/rpn55
Screenshots
Verdict
The clearest difference is price: WP 34s at Free against RPN's $1.99. WP 34s also leads on ratings volume (28 vs 8). RPN's advantage is rating (5.0 vs 4.7). On review sentiment, update cadence, ads and in-app purchases 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
WP 34s is free to download; RPN costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
RPN holds the better App Store score, 5.0 against 4.7. Both are backed by a comparable volume of ratings — 28 and 8 respectively. Written reviews point the same way: 93% of WP 34s's written reviews are positive against 100% of RPN's.
WP 34s ships an update every 4 months, RPN every 3 months. The most recent releases landed on September 20, 2026 and September 6, 2026 respectively.
| Parameter | WP 34s | RPN |
|---|---|---|
| Price | Free — better | $1.99 |
| Rating | 4.7 (28 ratings) | 5.0 (8 ratings) — better |
| Positive reviews | 92.6% of reviews | 100.0% of reviews — better |
| Number of ratings | 28 — better | 8 |
| Update frequency | Every 4 months | Every 3 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free — better | Paid |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 12.0 | 12.0 |
| Further details — not scored | ||
| Size | 11 MB | 17 MB |
| Age rating | 4+ | 4+ |
| Developer | Pascal Meheut | CuVee Software |
Customer experience
WP 34s
RPN
In-app purchases
WP 34s
No in-app purchases
RPN
No in-app purchases







