picocalc vs RPN
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
picocalc
This app displays a single number on your home screen badge, which can be set, added to, or subtracted from. It's a minimalist tool for quick numerical reminders. Negative numbers and zero are not displayed on the badge.
- Set a number
- Add to number
- Subtract from number
- Home screen badge display
- Hides zero and negative numbers
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picocalc is a tiny number memo which can be set, added and subtracted. The number is show as an application badge in the home screen. Zero and a negative number won't be shown in the badge.
RPN
This app simulates a legendary scientific calculator, offering photo-realistic visuals and advanced functions like integration and root finding. It includes built-in programs and extensions for enhanced usability, making it a powerful tool for complex calculations.
- Photo-realistic look-and-feel
- Programmable with 999 steps
- Integration and root solving
- Built-in application programs
- Live register view
- Program library and backup
- Sharing via email, AirDrop, Dropbox
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RPN-34 CE is the first photo-realistic simulation of Hewlett-Packard's popular mid-range scientific calculator HP-34C for the iPhone. Produced from 1979 through 1983, it was the "Basil" member of the third-generation HP calculators known as the "Spice" series. It was the first pocket-calculator ever capable of doing integration and root finding. While the simulator works like the original calculator, a number of carefully designed extensions, along with the tremendously improved speed, make it joy to use even today. RPN-34 CE comes with the programs of HP's "Applications", "Mathematics", "Surveying", "Student Engineering", and "Statistics" application books built-in! Handbooks may be downloaded from CuVee Software's website. Features: • Photo-realistic look-and-feel • Programmable (999 steps), subroutines, 12 labels, 10 flags • 100 registers, "continuous", with full store/recall arithmetic • "Live" register view • Program listing view with intelligent navigation • Program library, easily backed-up via iTunes • Store and retrieve any number of programs • Sharing: e-mail, AirDrop, Dropbox, copy, paste, print • 62 programs pre-installed (53 original HP) Calculator functions: • Integration, root solving • Statistics (mean, standard deviation, linear regression, normal distribution) • Factorial of any number (normal and logarithmic) • Trigonometric and hyperbolic functions (degrees, radians, grads) • Polar/rectangular conversions • Inverse, square root, logarithm, exponential, pi • Storage arithmetic (both store and recall) • Statistics (average, standard deviation, y-estimate, linear regression) • Unit and hours conversions • 31 additional functions not found on the HP-34C, like time and sound Details: cuveesoft.ch/rpn34
Screenshots
Verdict
The clearest difference is price: picocalc at Free against RPN's $1.99. picocalc also leads on device support (4 vs 2). RPN's advantage is in-app purchases (none vs 1) and ads (none vs shown). On rating 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
picocalc is free to download; RPN costs $1.99 up front. picocalc sells 1 one-off in-app purchase. RPN asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 5.0 for picocalc against 5.0 for RPN. Both are backed by a comparable volume of ratings — 3 and 14 respectively. Written reviews are what separate them: 66% of picocalc's written reviews are positive against 100% of RPN's.
picocalc ships an update every 16 months, RPN every 3 months. The most recent releases landed on October 25, 2026 and October 29, 2026 respectively.
| Parameter | picocalc | RPN |
|---|---|---|
| Price | Free — better | $1.99 |
| Rating | 5.0 (3 ratings) | 5.0 (14 ratings) |
| Positive reviews | 65.6% of reviews | 100.0% of reviews — better |
| Number of ratings | 3 | 14 — better |
| Update frequency | Every 16 months | Every 3 months — better |
| Ads | Yes | No — better |
| In-app purchases | Yes | No — better |
| Monetization | Free — better | Paid |
| Best chart rank | — | #69 — better |
| Devices | iPhone, iPad, Apple Watch, Vision Pro — better | iPhone, iPod |
| Requires iOS | 17.6 | 12.0 — better |
| Further details — not scored | ||
| Size | 6 MB | 16 MB |
| Age rating | 4+ | 4+ |
| Developer | Masayuki Akamatsu | CuVee Software |
Customer experience
picocalc
RPN
In-app purchases
picocalc
- Remove Ads$0.99
RPN
No in-app purchases









