# i41CX+ vs RLM

The clearest difference is price: RLM at Free against i41CX+'s $24.99. i41CX+'s advantage is rating (4.8 vs 4.1) and in-app purchases (none vs 4). On update cadence, ads, device support and iOS requirement 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.

i41CX+ holds the better App Store score, 4.8 against 4.1. That said, the two scores are not equally well evidenced: i41CX+ has 107 ratings behind it against 17, so its average is the more settled of the two. Written reviews point the same way: 91% of i41CX+'s written reviews are positive against 80% of RLM's.

i41CX+ ships an update every 5 weeks, RLM monthly. The most recent releases landed on October 17, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | i41CX+ | RLM |
| --- | --- | --- |
| Price | $24.99 | **Free** |
| Rating | **[4.8 (107 ratings)](https://appshunter.io/ios/app/i41cx-plus/id289068865/reviews)** | [4.1 (17 ratings)](https://appshunter.io/ios/app/rlm-15cx/id1636646608/reviews) |
| Number of ratings | **107** | 17 |
| Positive reviews | **91.3% of reviews** | 80.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 5 weeks | **Monthly** |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 124 MB | 6 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| 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 Computer Algebra System (CAS) capabilities, going beyond traditional replicas. It provides access to an extensive library of modules and programs, enhanced with iOS features, customizable skins, and iCloud support for seamless data management.

**Highlights:** RPN logic with 4-element stack, Extensive memory registers, Over 400 built-in functions, Computer Algebra System (CAS), Virtual thermal printer/plotter, Access to HP-41 module library, Customizable skins and keyboard overlays

**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-15cx/id1636646608)

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:** macOS Compatibility, Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Subscription | $0.49 | per month |
| Semi-Annual Subscription | $2.99 | per 6 months |
| Annual Subscription | $5.99 | per year |
| One-Time 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?

i41CX+ is rated higher. i41CX+ averages 4.8 out of 5 from 107 ratings, while RLM averages 4.1 from 17 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 5 weeks, and RLM monthly. Most recently, i41CX+ was updated on October 17, 2026 and RLM on October 15, 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.*