Comparison

RPN vs RLM

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

Head to head
About

RPN

This app is a faithful simulation of a rare 1974 financial calculator, offering all its original functions with enhanced features like more memory registers and a visual stack display. It's designed for users who appreciate vintage technology and need precise financial calculations.

Highlights
  • Photo-realistic vintage calculator design
  • Full HP-70 function simulation
  • Animated keys with sound
  • Enhanced stack and memory register view
  • Cut/copy/paste display value
  • Input parameter visual indicators
Features
Read full description

RPN-70 SD is a complete simulation of the financial hand-held calculator HP-70 from 1974. It handles loan amortization, saving plans, depreciation, and much more with ease. What users said: "Looks good, all functions you need. Love it!" "This is a beautiful emulation of a very rare HP financial calculator from 1974. Works just like the original but better! Faster, more accurate, with 10 more storage registers, and a popup window lets you see the contents of each stack, financial and storage register. Provides TVM4 functionality for compound interest as well as accumulated simple interest. A true work of art!" Features: • Photo-realistic look based on an existing device • Animated keys with click sound (adjustable volume) • All functions and operations of the HP-70 fully implemented • Correct wrong number entries by swiping across the display • Cut/copy/paste of display value • Double-tap display to view the stack and memory registers • Visual indicators keep track of input parameters entered • 10 non-volatile memory registers (not available in original HP-70) The HP-70 was discontinued after just one year. It is one of the rarest calculators, hard to find in any condition. NOTE: RPN-70 SD is a faithful simulation of a vintage HP-70 calculator, as has been verified against a real device using the examples in the Applications Cookbook section of the HP-70 manual. In certain cases, what may appear like a bug of the app is actually an idiosyncrasy of the HP-70. IMPORTANT: The HP-70 requires exactly three input parameters from the top-row keys, at least one of them being either "n" or "i". In other words, you can't use PMT, PV, and FV as input parameters simultaneously. A version for the iPhone named "RPN-70 HD" is also available. Short manual and sample calculations on the website: www.cuveesoft.ch

About

RLM

This advanced scientific calculator emulates the functionality of the HP-15C, offering comprehensive tools for finance, business, statistics, and scientific calculations. It supports programming, equation solving, and unit conversions, optimized for iOS devices.

Highlights
  • Programmable advanced scientific calculator
  • Finance and business calculation menus
  • Statistics and probability functions
  • Complex numbers and matrix operations
  • Unit and currency conversions
  • Equation solver and programming capabilities
Features
Read full description

The RLM-15CX application is a programable advanced scientific calculator. It is based in the Hewlett-Packard HP-15C calculator, but specially designed to bring up the most of your iOS devices and , at the same time, conserving the easy of use and the functionality 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 Cash Flows: Solve problems where different cash flows occur at regular time intervals. •Unequal Periods Cash Flows: Solve problems where different cash flows occur at different dates. •Depreciation: Calculates depreciation with SL, SOYD, DB or MACRS methods and conventions. values at sight. •Interest Rates: 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. •Matrix: view, create or edit matrices with real or complex elements. •Plane Triangle: Solves a two dimensional triangle (ASA,SAS,SSA and SSS). •Spherical Triangle: Solves a triangle in a sphere’s surface (AAA,AAS,ASA,SAS,SSA and SSS). •Universal Constants: All the NIST-CODATA fundamental physical constants. •Vectors 3D: Operations and functions with vectors in Cartesian, Spherical or Cylindrical coordinates. >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. •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

RPN4 screens
RLM4 screens

Verdict

The call

The clearest difference is rating: RPN at 4.7 against RLM's 4.1. RPN also leads on in-app purchases (none vs 4) and review sentiment (100% vs 80%). RLM's advantage is update cadence (monthly vs every 7 months). On price, ratings volume, 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

CostPrice · In-app purchases · Ads · Monetization

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

ReceptionRating · Positive reviews · Number of ratings

RPN holds the better App Store score, 4.7 against 4.1. Both are backed by a comparable volume of ratings — 11 and 18 respectively. Written reviews point the same way: 100% of RPN's written reviews are positive against 80% of RLM's.

UpkeepUpdate frequency

RPN ships an update every 7 months, RLM monthly. The most recent releases landed on October 31, 2026 and October 30, 2026 respectively.

Scorecard6 real differences · 4 level
RPN versus RLM: the parameters behind the verdict, then further details
ParameterRPNRLM
PriceFreeFree
Rating4.7 (11 ratings) — better4.1 (18 ratings)
Positive reviews100.0% of reviews — better80.0% of reviews
Number of ratings1118 — better
Update frequencyEvery 7 monthsMonthly — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS12.0 — better15.0
Further details — not scored
Size17 MB6 MB
Age rating4+4+
DeveloperCuVee SoftwareR.L.M. Software

Customer experience

RPN

All ratings11 ratings
Positive90.9%
Neutral9.1%
Negative0.0%
Written reviews9 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

RLM

All ratings18 ratings
Positive72.2%
Neutral11.1%
Negative16.7%
Written reviews15 reviews
Positive80.0%
Neutral13.3%
Negative6.7%

In-app purchases

None

RPN

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
  • One-Time Purchase$9.99

Questions

Is RPN free?
RPN 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, RPN or RLM?
RPN is rated higher. RPN averages 4.7 out of 5 from 11 ratings, while RLM averages 4.1 from 18 ratings.
Do RPN or RLM have ads?
Neither RPN nor RLM shows ads.
Which is updated more often, RPN or RLM?
RPN ships an update every 7 months, and RLM monthly. Most recently, RPN was updated on October 31, 2026 and RLM on October 30, 2026.

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