Free42 vs my41CX
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Free42
This application is a faithful re-implementation of the HP-42S scientific calculator and its associated printer. It offers full functionality without requiring original HP ROM images and is an open-source project.
- HP-42S calculator simulation
- HP-82240 printer simulation
- Open source project
- No HP ROM required
- Complete rewrite
Read full descriptionHide full description
Free42 is a re-implementation of the HP-42S calculator and the HP-82240 printer. It is a complete rewrite, not using any HP code, and it does not require an HP-42S ROM image. Free42 is an Open Source project. The executables and source code are released under the terms of the GNU General Public License, version 2. All third-party code used in Free42 is either in the public domain, or licensed under terms compatible with GPLv2, or used with the authors' permission.
my41CX
Experience the most accurate HP-41CX calculator emulation. This app provides full microcode-level emulation of the original NUT processor, ensuring 100% hardware-accurate behavior. It features a modern interface, expandable ROM modules, and built-in documentation for a classic yet contemporary user experience.
- True microcode emulation
- Modern user interface
- Expandable with ROM modules
- Built-in documentation
- 100% hardware-accurate behavior
Read full descriptionHide full description
The most accurate HP-41CX emulator available. my41cx delivers full microcode-level emulation of the legendary NUT processor, reproducing every behavior of the original hardware with complete fidelity. Built and refined over three major releases, my41cx v3 combines the precision of real hardware emulation with a modern interface designed for daily use. Key Features: - True Microcode Emulation: Not a simulation—an actual NUT processor emulator running original microcode for 100% hardware-accurate behavior. - Modern Interface, Classic Soul: A completely redesigned UI built for today's devices while preserving the authentic feel of the original calculator. - Expandable with ROM Modules: Load external ROM modules to extend the system, just like the real HP-41CX. - Built-in Documentation: Access manuals and reference material directly within the app—no need to search for PDFs. Perfect for engineers, students, scientists, and anyone who appreciates the elegance of HP's finest programmable calculator. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Screenshots
Verdict
The clearest difference is review sentiment: Free42 at 94% against my41CX's 43%. Free42 also leads on in-app purchases (none vs 3) and ratings volume (287 vs 1). my41CX's advantage is rating (5.0 vs 4.8). On price, ads 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
Both are free to download. my41CX sells 3 in-app purchases, starting at $0.99 per month. Free42 asks for nothing beyond the download.
my41CX holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: Free42 has 287 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 94% of Free42's written reviews are positive against 43% of my41CX's, so the app with the better star average is not the one people write more warmly about.
Free42 ships an update every 9 days, my41CX every 2 months. The most recent releases landed on October 26, 2026 and October 23, 2026 respectively.
| Parameter | Free42 | my41CX |
|---|---|---|
| Price | Free | Free |
| Rating | 4.8 (287 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 94.4% of reviews — better | 43.4% of reviews |
| Number of ratings | 287 — better | 1 |
| Update frequency | Every 9 days — better | Every 2 months |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Mac |
| Requires iOS | 15.0 — better | 26.0 |
| Further details — not scored | ||
| Size | 9 MB | 5 MB |
| Age rating | 4+ | 4+ |
| Developer | Thomas Okken | Miroslav Perovic |
Customer experience
Free42
my41CX
User reviews
Free42
From 287 App Store ratingsWhat we love
- 🚀 Faithful reproduction of HP42S
- 👍 Identical to physical calculator
- 👍 Runs all original programs
- 👍 Convenient to have on phone
- 👍 Haptic feedback on button presses
Room to improve
- 🐛 Screen not filling entire display on newer devices
- 🔇 Configurable key click sound missing
- 🔇 Lack of loud click sound feedback
my41CX
From 1 App Store ratingsWhat we love
- 👍 Excellent emulation of HP calculators
- ✨ Faithful look and feel
- 💯 Perfect functionality
- 🚀 Works perfectly on phones/iPads
- 💡 Great for RPN calculator users
Room to improve
- 🐛 Buggy on Mac
- 🤏 Small characters on buttons
- 🐛 Locks up when running programs
- 🐛 Crashes under iOS 13.2.3
- 🐛 Application quits after touching screen
Bugs and requests
Free42
Reported bugs
2 issues- Occasional issues with Solver function
- Store and Recall functions not working properly
Requested features
3 requests- Display all registers (X, Y, Z, T, Last X) simultaneously
- Ability to share/transfer programs between devices
- Improved use of screen real estate on larger displays
my41CX
Reported bugs
38 issues- Cannot enter anything via keyboard on Mac
- Locks up when running a program
- Crashes under IOS 13.2.3
- Application quits after touching screen
- Keys 'V' and 'W' inverted when ALPHA mode is switched on
Show 33 moreShow fewer
- GUI no longer accurate visual reproduction
- Incompatible with IOS 13.2
- Crashes systematically on hitting any key
- App closes after launch
- Not functional
- Unusable
- Crashes on startup
- App closes when touching keys
- Reverts to main screen when pressing buttons
- Flashes on screen and disappears
- Instant shutdown when trying to use it
- Shuts down as soon as screen is touched
- Shuts down when attempting to tap any key
- Crashes constantly after IOS update
- Closes the app as soon as you touch the screen
- Stopped working with iso 13.3
- Crashes as soon as I touch a key
- Broken on iOS 13.2
- Font for unshifted keys too small
- Functions faint and blurry
- Freezes when executing commands
- Low contrast
- No key feedback
- Unstable and crashes
- Slow performance
- Stopwatch function not real time
- Memory not reliably retained
- Loses all work
- Massive memory leaks
- Trashes program
- Incredibly slow
- Locks up
- Glitches while switching modes
Requested features
5 requests- Larger buttons
- Option for tactile/Haptic feedback for keys
- Option for beep sound
- Instructions for mod files
- Better Mac UI
In-app purchases
Free42
No in-app purchases
my41CX
- Monthly$0.991 Month
- Yearly Premium$9.991 Year
- Unlock Full App$19.99
