# i41CX+ vs RLM

The clearest difference is price: RLM at Free against i41CX+'s $24.99. RLM also leads on rating (5.0 vs 4.8). i41CX+'s advantage is review sentiment (91% vs 53%) and in-app purchases (none vs 4). On ads and device support there is nothing between them.

RLM is free to download; i41CX+ costs $24.99 up front. RLM sells 4 in-app purchases, starting at $0.49 per month. i41CX+ asks for nothing beyond the download.

RLM holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: i41CX+ has 108 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 91% of i41CX+'s written reviews are positive against 53% of RLM's, so the app with the better star average is not the one people write more warmly about.

i41CX+ ships an update every 6 days, RLM monthly. The most recent releases landed on November 6, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | i41CX+ | RLM |
| --- | --- | --- |
| Price | $24.99 | **Free** |
| Rating | [4.8 (108 ratings)](https://appshunter.io/ios/app/i41cx-plus/id289068865/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/rlm-17bx-calculator/id1593889938/reviews)** |
| Number of ratings | **108** | 1 |
| Positive reviews | **91.4% of reviews** | 53.3% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 6 days** | Monthly |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 124 MB | 7 MB |
| Requires iOS | **16.0** | 26.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Antonio Lagana](https://appshunter.io/developer/289068868) | [R.L.M. Software](https://appshunter.io/developer/289639238) |

## What reviewers say

### i41CX+

[App page](https://appshunter.io/ios/app/i41cx-plus/id289068865)

This advanced RPN scientific calculator offers workstation-class CAS capabilities and a virtual thermal printer. It emulates the HP-41CX, providing access to its modules and programs, enhanced with modern iOS features and extensive customization options. Perform complex calculations, symbolic algebra, and 2D/3D plotting without an internet connection.

**Highlights:** RPN logic with 4-element stack, Virtual thermal printer/plotter, Workstation-class Computer Algebra System (CAS), Emulates HP-41CX with module access, Extensive customization (skins, colors, keyboard), iCloud support for syncing, Offline operation

**Features:** macOS Compatibility, iPhone Duo support

**In-app purchases:** none

**What reviewers like**

- 🚀 Fantastic emulation of the original HP41 calculator
- 🔒 Faithful to the original hardware and functionality
- 👍 Includes all the expansion modules and accessories
- 👍 Responsive and never crashes
- 👍 Excellent implementation of RPN and programmability

**What reviewers complain about**

- 🔋 Can drain battery when left on
- 👎 Small button size can lead to mis-taps
- 👎 Slow startup time in some versions

**Reported bugs**

- Issues with the 41Z math module producing garbled output
- Scaling problems with overlays

**Requested features**

- Landscape mode for better button size
- Haptic feedback for button presses
- Ability to load and save programs/modules via cloud/email
- Macros or scripting support


### RLM

[App page](https://appshunter.io/ios/app/rlm-17bx-calculator/id1593889938)

This app offers a comprehensive suite of calculators for finance, business, science, and general use. It includes specialized worksheets for loans, investments, statistics, and complex mathematical functions, designed to leverage iOS device capabilities.

**Highlights:** Finance worksheets (amortization, bond pricing, options), Business calculations (bill split, break-even, currency), Statistical analysis (probability, regressions), Scientific functions (complex numbers, vectors), Unit and currency conversions, Equation solver, Date and time calculations

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Virtual Battery | $0.49 | per month |
| Semi-Annual Subscription | $2.99 | per 6 months |
| Annual Subscription | $5.99 | per year |
| Lifetime Purchase | $9.99 | one-time |


## Frequently asked questions

### Is i41CX+ free?

i41CX+ costs $24.99, with no in-app purchases.

### Is RLM free?

RLM is free to download, with in-app purchases available.

### Which has better reviews, i41CX+ or RLM?

RLM is rated higher. i41CX+ averages 4.8 out of 5 from 108 ratings, while RLM averages 5.0 from 1 ratings.

### Do i41CX+ or RLM have ads?

Neither i41CX+ nor RLM shows ads.

### Which is updated more often, i41CX+ or RLM?

i41CX+ ships an update every 6 days, and RLM monthly. Most recently, i41CX+ was updated on November 6, 2026 and RLM on November 3, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*