RLM vs Calccis
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
Calccis
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Calccis is a reverse polish notation (RPN) calculator. It supports basic arithmetic, trigonometrical, logarithm and exponent calculations for real, fractional, and complex numbers. Degrees and radians can be used for trigonometrical functions. You can perform matrix calculations, too. There is an undo stack, which supports undoing and redoing the 100 latest operations. Calccis does not copy or mimic any existing physical calculators. However, the operation of the stack has been influenced by how the stack works in the 1990s Hewlett-Packard HP-48 family of calculators.
Screenshots
Verdict
The clearest difference is in-app purchases: Calccis at none against RLM's 4. RLM's advantage is iOS requirement (15.0 vs 17.6). On price, update cadence, 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. RLM sells 4 in-app purchases, starting at $0.49 per month. Calccis asks for nothing beyond the download.
RLM ships an update every 5 weeks, Calccis every 3 weeks. The most recent releases landed on September 30, 2026 and September 12, 2026 respectively.
| Parameter | RLM | Calccis |
|---|---|---|
| Price | Free | Free |
| Rating | 3.1 (7 ratings) — better | — |
| Positive reviews | 66.7% of reviews | — |
| Number of ratings | 7 — better | — |
| Update frequency | Every 5 weeks | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | — |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.0 — better | 17.6 |
| Further details — not scored | ||
| Size | 6 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | R.L.M. Software | Jukka Aittola |
In-app purchases
RLM
- Monthly Subscription$0.491 Month
- Semi-Annual Subscription$2.996 Months
- Annual Subscription$5.991 Year
- Lifetime Purchase$9.99
Calccis
No in-app purchases









