my41CX vs RLM
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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
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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/
RLM
This scientific calculator offers a comprehensive suite of tools for finance, business, statistics, and complex scientific calculations. It emulates a classic calculator while leveraging modern iOS device capabilities for ease of use and advanced functions.
- Finance and Business calculations
- Date and Time interval calculations
- Advanced Statistics and Curve Fitting
- Complex Numbers and 3D Vectors
- Unit and Currency Conversions
- Equation Solver
- Programmable functions
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The RLM-10CX application is a general purpose calculator with a special focus in science and engineering. It is based in the Hewlett-Packard HP-10C calculator, but specially designed to bring up the most of your iOS devices and , at the same time, conserving the easy of use and all functions originally provided by the real calculator. >Finance Menu: •Account Balance: Credit line type account based on cash transactions and interest rates applied. •Amortization: Loan Amortization Schedule for a single loan payment or from several payments at once. •Bond Price & Yield: Bonds calculations in an easy way with all options and values at sight. •Black-Scholes Options: CALL, PUT and “Greeks” calculations of the Black-Scholes European option valuation model. •Equal Periods: Calculations with Cash Flows occurring at regular time intervals. •Unequal Periods: Calculations with Cash Flows occurring at arbitrary dates. •Depreciation: Calculates depreciation with SL, SOYD, DB or MACRS methods and conventions. values at sight. •Interest Conversion: Nominal and effective interest conversion. •Time Value of Money: Compound Interest problems involving money earning interest over a period of time. >Business Menu: •Bill-Tip-Split: Calculates the sharing of a Bill with Tip. •Break-Even: Analyze the following relation: Profit = (Price - Var.Cost) • Units - Fix.Cost •Currency Exchange with on-line rates. •Percents & Margins: Calculates %Change, %Total and Business margins. Date / Time Menu: Calculates Date and Time intervals with all values at sight. >Statistics Menu: •One-Variable Statistics: Calculations for one variable data samples. •Two-Variable Statistics: Calculations for two variables data samples. •Curve Fitting: 6 Regression models to fit a curve based on two variables data samples. •Probability: Combinations, permutations, Normal, Exponential, t-Student and Weibull probability distributions. >Scientific Menu: •Complex Numbers: Operations and functions with complex numbers. •Logarithms, Trigonometric, Hyperbolic and Number Alteration functions. •Triangle Solution: Solves a Plane & Spherical triangles. •3D Vectors: Operations and functions with vectors in Cartesian, Spherical or Cylindrical coordinates. •Universal Constants: All the NIST-CODATA physical constants values and descriptions. •Units Conversion: Physical units conversion completely customizable. >Convert Menu: •Angles & Polar: Convert angles between DEG,RAD,GRAD,DMS or Slope % & Polar-Rectangular coordinates. •Currencies: world currencies conversions with manual input or on-line current rates. •Interest Rates: Nominal and effective interest conversion. •Units: Physical units conversions. >Program Menu: Create, edit or load previously saved programs. >Solver Menu: Solve arbitrary algebraic equations entered and saved in the equation editor and creates a menu with all the variables to solve any of them. >Utilities Menu: •General Settings: Customize the calculator to your preference. •Storage Registers: Store and perform operations directly over the calculator’s storage registers. •Memory Content: Shows all memory content edit, backup or restore. •Help Documents: learn by example about all menus. >Editors: submenu to select data editors. System requirements: iOS 15.0 or above. 30 days Free-Trial. In-App-Purchase: One-Payment for life. License Agreement: http://www.apple.com/legal/itunes/appstore/dev/stdeula Disclaimer: THIS IS NOT A HEWLETT PACKARD CALCULATOR, AND IS NOT SPONSORED IN ANYWAY BY HEWLETT PACKARD OR ANY OF ITS SUBSIDIARIES.
Screenshots
Verdict
The clearest difference is monetization model: RLM at free against my41CX's free with in-app purchases. RLM also leads on update cadence (every 4 weeks vs every 2 months) and iOS requirement (15.0 vs 26.0). On price, rating, ratings volume 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. my41CX sells 3 in-app purchases, starting at $0.99 per month and RLM sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 5.0 for my41CX against 5.0 for RLM. Both are backed by a comparable volume of ratings — 1 and 1 respectively.
my41CX ships an update every 2 months, RLM every 4 weeks. The most recent releases landed on September 26, 2026 and September 10, 2026 respectively.
| Parameter | my41CX | RLM |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) | 5.0 (1 ratings) |
| Positive reviews | 43.4% of reviews | — |
| Number of ratings | 1 | 1 |
| Update frequency | Every 2 months | Every 4 weeks — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad, Mac | iPhone, iPad, iPod |
| Requires iOS | 26.0 | 15.0 — better |
| Further details — not scored | ||
| Size | 5 MB | 6 MB |
| Age rating | 4+ | 4+ |
| Developer | Miroslav Perovic | R.L.M. Software |
Customer experience
my41CX
RLM
Bugs and requests
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
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- 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
RLM
Not enough reviews yet to summarise bugs or requests.
In-app purchases
my41CX
- Monthly$0.991 Month
- Yearly Premium$9.991 Year
- Unlock Full App$19.99
RLM
- Lifetime Purchase$9.99








