RPN vs RLM
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
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.
- 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
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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
Verdict
The clearest difference is review sentiment: RPN at 93% against RLM's 40%. RPN also leads on rating (4.6 vs 3.1) and in-app purchases (none vs 4). RLM's advantage is price (Free vs $3.99) and update cadence (every 5 weeks vs every 3 months). On 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
RLM is free to download; RPN costs $3.99 up front. RLM sells 4 in-app purchases, starting at $0.49 per month. RPN asks for nothing beyond the download.
RPN holds the better App Store score, 4.6 against 3.1. Both are backed by a comparable volume of ratings — 17 and 7 respectively. Written reviews point the same way: 93% of RPN's written reviews are positive against 40% of RLM's.
RPN ships an update every 3 months, RLM every 5 weeks. The most recent releases landed on November 4, 2026 and November 3, 2026 respectively.
| Parameter | RPN | RLM |
|---|---|---|
| Price | $3.99 | Free — better |
| Rating | 4.6 (17 ratings) — better | 3.1 (7 ratings) |
| Positive reviews | 92.9% of reviews — better | 40.0% of reviews |
| Number of ratings | 17 — better | 7 |
| Update frequency | Every 3 months | Every 5 weeks — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid | Free with in-app purchases — better |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 12.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 63 MB | 6 MB |
| Age rating | 4+ | 4+ |
| Developer | CuVee Software | R.L.M. Software |
Customer experience
RPN
RLM
In-app purchases
RPN
No in-app purchases
RLM
- Monthly Subscription$0.491 Month
- Semi-Annual Subscription$2.996 Months
- Annual Subscription$5.991 Year
- Lifetime Purchase$9.99








