# i41CX vs RPN

The clearest difference is in-app purchases: RPN at none against i41CX's 4. RPN also leads on rating (5.0 vs 4.6) and price ($1.99 vs $7.99). i41CX's advantage is update cadence (every 5 weeks vs every 3 months) and ratings volume (45 vs 8). On ads, device support and iOS requirement there is nothing between them.

i41CX costs $7.99 and RPN $1.99 up front. i41CX sells 4 one-off in-app purchases. RPN asks for nothing beyond the download.

RPN holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: i41CX has 45 ratings behind it against 8, so its average is the more settled of the two. Written reviews point the same way: 90% of i41CX's written reviews are positive against 100% of RPN's.

i41CX ships an update every 5 weeks, RPN every 3 months. The most recent releases landed on September 26, 2026 and September 25, 2026 respectively.

## The numbers

| Metric | i41CX | RPN |
| --- | --- | --- |
| Price | $7.99 | **$1.99** |
| Rating | [4.6 (45 ratings)](https://appshunter.io/ios/app/i41cx/id292619450/reviews) | **[5.0 (8 ratings)](https://appshunter.io/ios/app/rpn-55-sd/id1469907917/reviews)** |
| Number of ratings | **45** | 8 |
| Positive reviews | 90.5% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 5 weeks** | Every 3 months |
| Monetization | **Free with in-app purchases** | Paid |
| Best chart rank | — | **#161** |
| Size | 134 MB | 17 MB |
| Requires iOS | 13.0 | **12.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | +4 | 4+ |
| Developer | [Antonio Lagana](https://appshunter.io/developer/289068868) | [CuVee Software](https://appshunter.io/developer/424873503) |

## What reviewers say

### i41CX

[App page](https://appshunter.io/ios/app/i41cx/id292619450)

This app offers a powerful RPN scientific calculator experience, functionally equivalent to a renowned model. It provides extensive memory registers, over 300 built-in functions, and programmability. Advanced features can be unlocked via in-app purchases.

**Highlights:** RPN logic with 4-element stack, 319 main and 124 extended memory registers, Over 300 built-in functions, Programmable up to 2000 lines, User-definable keyboard, Bluetooth keyboard support, Device integration features

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Overlays Upgrade | $2.99 | one-time |
| Printer Upgrade | $3.99 | one-time |
| CAS Upgrade | $7.99 | one-time |
| i41CX+ Features Upgrade | $17.99 | one-time |


### RPN

[App page](https://appshunter.io/ios/app/rpn-55-sd/id1469907917)

**Currently charting:** #161 Top Paid · Productivity (US App Store)

This app is a photo-realistic simulation of a classic Hewlett-Packard programmable scientific calculator from the 1970s. It includes a 100-hour digital timer, clock functions, and original HP programs.

**Highlights:** Photo-realistic look-and-feel, Programmable with conditional branching, 100-hr timer and 12/24-hr clock, Original HP programs built-in, Extended features for enhanced usability, Sharing via email, AirDrop, and more

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is i41CX free?

i41CX costs $7.99, and also offers in-app purchases.

### Is RPN free?

RPN costs $1.99, with no in-app purchases.

### Which has better reviews, i41CX or RPN?

RPN is rated higher. i41CX averages 4.6 out of 5 from 45 ratings, while RPN averages 5.0 from 8 ratings.

### Do i41CX or RPN have ads?

Neither i41CX nor RPN shows ads.

### Which is updated more often, i41CX or RPN?

i41CX ships an update every 5 weeks, and RPN every 3 months. Most recently, i41CX was updated on September 26, 2026 and RPN on September 25, 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.*