Comparison

Free42 vs RLM

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

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.

Highlights
  • HP-42S calculator simulation
  • HP-82240 printer simulation
  • Open source project
  • No HP ROM required
  • Complete rewrite
Features
Read 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.

About

RLM

This app is a scientific and programmable calculator designed for science and engineering, replicating the functionality of the HP-11C. It offers extensive features for finance, business, statistics, complex numbers, and unit conversions, with a programmable interface for custom calculations.

Highlights
  • Finance calculations (amortization, bond price, Black-Scholes)
  • Business functions (break-even, currency exchange)
  • Statistical analysis (regression, probability distributions)
  • Scientific functions (complex numbers, logarithms, trigonometry)
  • Unit and currency conversions
  • Programmable interface for custom scripts
  • Equation solver
Features
Read full description

The RLM-11C+ application is a general purpose calculator with a special focus science and engineering. It is based in the Hewlett-Packard HP-11C 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

Free423 screens
RLM4 screens

Verdict

The call

The clearest difference is review sentiment: Free42 at 94% against RLM's 40%. Free42 also leads on rating (4.8 vs 3.1) and in-app purchases (none vs 4). On price, ads, device support and iOS requirement 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. RLM sells 4 in-app purchases, starting at $0.49 per month. Free42 asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Free42 holds the better App Store score, 4.8 against 3.1. That said, the two scores are not equally well evidenced: Free42 has 287 ratings behind it against 7, so its average is the more settled of the two. Written reviews point the same way: 94% of Free42's written reviews are positive against 40% of RLM's.

UpkeepUpdate frequency

Free42 ships an update every 9 days, RLM every 5 weeks. The most recent releases landed on October 29, 2026 and October 30, 2026 respectively.

Scorecard6 real differences · 4 level
Free42 versus RLM: the parameters behind the verdict, then further details
ParameterFree42RLM
PriceFreeFree
Rating4.8 (287 ratings) — better3.1 (7 ratings)
Positive reviews94.4% of reviews — better40.0% of reviews
Number of ratings287 — better7
Update frequencyEvery 9 days — betterEvery 5 weeks
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.015.0
Further details — not scored
Size9 MB6 MB
Age rating4+4+
DeveloperThomas OkkenR.L.M. Software

Customer experience

Free42

All ratings287 ratings
Positive93.7%
Neutral2.4%
Negative3.8%
Written reviews178 reviews
Positive94.4%
Neutral1.7%
Negative3.9%

RLM

All ratings7 ratings
Positive42.9%
Neutral14.3%
Negative42.9%
Written reviews5 reviews
Positive40.0%
Neutral0.0%
Negative60.0%

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

RLM

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Free42

No in-app purchases

4 purchases

RLM

Subscriptions3
  • Monthly Subscription$0.491 Month
  • Semi-Annual Subscription$2.996 Months
  • Annual Subscription$5.991 Year
One-time1
  • Lifetime Purchase$9.99

Questions

Is Free42 free?
Free42 is free to download, with no in-app purchases.
Is RLM free?
RLM is free to download, with in-app purchases available.
Which has better reviews, Free42 or RLM?
Free42 is rated higher. Free42 averages 4.8 out of 5 from 287 ratings, while RLM averages 3.1 from 7 ratings.
Do Free42 or RLM have ads?
Neither Free42 nor RLM shows ads.
Which is updated more often, Free42 or RLM?
Free42 ships an update every 9 days, and RLM every 5 weeks. Most recently, Free42 was updated on October 29, 2026 and RLM on October 30, 2026.

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