RPN vs Flipper Mobile App
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
RPN
This app simulates a vintage programmable calculator from the mid-70s, offering enhanced features beyond the original. It allows users to run existing programs, manage virtual cards, and utilize advanced functions for scientific and engineering tasks.
- Virtual program and data cards
- Virtual paper tape printer
- Database-driven card manager
- Create, label, and organize unlimited cards
- Share cards via email, AirDrop, Dropbox
- Editable program listings
- Enhanced features for more program steps and registers
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A dream calculator of the mid-70's, priced at $2,500 in today's dollars (2025), right on your iPhone! RPN-67 SD is the iPhone version of RPN-67 Pro, the first complete simulation of Hewlett-Packard's legendary HP-67 programmable calculator for the iPad. Produced from 1976 to 1982, the HP-67 was a huge success among scientists, engineers and other professionals. Thousands of programs were written for it. Now you can run them right on your iPhone, with more ease and faster than ever before. To get you started quickly, run the built-in program cards, or choose from the large number of programs available as free downloads from our website. What users said: “This version permits you to use your virtual HP-67 just as you could the original – hand-held and highly portable. Congratulations to the developer for providing such an excellent and aesthetically pleasing software product." "This was my first scientific calculator in real life. It is great to have the simulator on my iPhone. The special features added make it into a HP-41 or 42S! It comes packaged with some great samples. Am having great fun with it." Features: • Virtual program and data cards • Virtual paper tape printer supports all HP-97 printer modes • Powerful database-driven card manager • Create, label, and organize a virtually unlimited number of cards • Use iTunes to effortlessly save entire card collections on your Mac/PC • Sharing: e-mail, AirDrop, Dropbox, copy, paste, print • Editable listing shows labels, targets of branches, and errors • E-mail listings and let the recipient paste the text right into RPN-67 • Print listings on any AirPrint-compatible printer • Program listing on paper tape shows subroutine nesting • Edit paper tape • E-mail paper tape, or print it via AirPrint • Cut/copy/paste displayed value or program steps • Paste existing HP-67 listings into RPN-67 SD and run them • "Live" display of stack, memory registers, flags • Show and edit program instructions • Fast: 1.5 seconds vs. 6 minutes (program HM-05, determinant of 5x5 matrix) • Low-battery indicator (iPhone charge 10% or less) • Optional high-contrast mode for working in bright ambient light • Compatible with RPN-67 Pro and RPN-97 Pro While RPN-67 SD works like a real HP-67, changing a simple setting will turn the app into a super-charged HP-67: • Up to 999 program steps, 8 subroutine levels, 6 additional flags (F4...F9) • 100 additional registers • 100 additional labels • 100 built-in constants and conversions • More than 150 additional powerful operations and functions Plus: • 15 commands to print and manipulate any range of extended registers • Unrestricted register arithmetic • Exchange x with any register • Complex numbers, hyperbolic functions • Non-volatile memory - stack, registers, program, flags, paper tape • Status indicators for prefix keys (f, g, h, STO, RCL, etc.) • Display showing thousands separators (optional) • Text output on simulated paper tape in 10 colors, even simple plotting • Stack-of-stack: push/pop the entire stack on internal stack (4 levels) • Single-step into subroutines (optional) • Powerful debugging aids, including 10 breakpoints with counters • Keycodes translated to command names while entering or single-stepping a program • Change the duration of the PAUSE command • Compress constants in programs into a single step (reversible) RPN-67 SD comes with more than 130 programs pre-installed, including HP Standard Pac, HP Business Decisions Pac, HP Math Pac I, HP Stat Pac I, and HP Surveying Pac I. The simulator has been verified to correctly run the examples given in HP Civil Engineering Pac I, HP Clinical Lab Pac, HP E.E. Pac I, HP Games Pac I, HP M.E. Pac I, HP Navigation Pac I, as well as large number of programs published in Users' Library Solutions. For more information and free program downloads visit the RPN-67 website: cuveesoft.ch/rpn67
Flipper Mobile App
Manage your portable multi-tool device data, organize digital keys, and share them with a community of users. This application enhances the functionality of your device for various geeky projects.
- Manage device data
- Organize digital keys
- Share keys with users
- Community sharing
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Flipper Zero is a portable multi-tool for geeks in a toy-like body. This app helps to manage your data on the device, organize keys and share them with other Flipper Zero users.
Screenshots
Verdict
The clearest difference is price: Flipper Mobile App at Free against RPN's $3.99. Flipper Mobile App also leads on update cadence (every 3 weeks vs every 3 months) and ratings volume (313 vs 17). RPN's advantage is review sentiment (93% vs 69%) and iOS requirement (12.0 vs 16.0). On rating, ads, in-app purchases and device support 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
Flipper Mobile App is free to download; RPN costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 4.6 for RPN against 4.5 for Flipper Mobile App. That said, the two scores are not equally well evidenced: Flipper Mobile App has 313 ratings behind it against 17, so its average is the more settled of the two. Written reviews are what separate them: 93% of RPN's written reviews are positive against 69% of Flipper Mobile App's.
RPN ships an update every 3 months, Flipper Mobile App every 3 weeks. The most recent releases landed on October 29, 2026 and October 24, 2026 respectively.
| Parameter | RPN | Flipper Mobile App |
|---|---|---|
| Price | $3.99 | Free — better |
| Rating | 4.6 (17 ratings) — better | 4.5 (313 ratings) |
| Positive reviews | 92.9% of reviews — better | 69.5% of reviews |
| Number of ratings | 17 | 313 — better |
| Update frequency | Every 3 months | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPod — better | iPhone |
| Requires iOS | 12.0 — better | 16.0 |
| Further details — not scored | ||
| Size | 63 MB | 17 MB |
| Age rating | 4+ | 4+ |
| Developer | CuVee Software | Flipper Devices Inc. |
Customer experience
RPN
Flipper Mobile App
Bugs and requests
RPN
Not enough reviews yet to summarise bugs or requests.
Flipper Mobile App
Reported bugs
5 issues- Firmware update process sometimes causes Bluetooth, SubGHz, or NFC issues
- App crashes when trying to access the App Store section
- Keyboard not showing up when pairing code is requested
- Widgets not working on iOS 16
- Remote control feature has input lag
Requested features
9 requests- More interactive features (e.g., sleeping dolphin, talking dolphin)
- Ability to download different firmware versions directly in the app
- Support for managing multiple Flipper Zero devices
- Folder support in SubGHz catalog
- Apple Watch companion app
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- Shortcuts integration for payloads
- Notification system for app updates
- Ability to edit and move files/folders on the Flipper Zero
- Ducky script compiler in the mobile app
In-app purchases
RPN
No in-app purchases
Flipper Mobile App
No in-app purchases









