# RPN Calc vs iCrucible

The clearest difference is price: iCrucible at Free against RPN Calc's $0.99. RPN Calc's advantage is in-app purchases (none vs 8). On update cadence, ads, device support and iOS requirement there is nothing between them.

iCrucible is free to download; RPN Calc costs $0.99 up front. iCrucible sells 8 in-app purchases, starting at $2.99 per month. RPN Calc asks for nothing beyond the download.

RPN Calc ships an update every 3 months, iCrucible every 5 months. The most recent releases landed on October 24, 2026 and October 27, 2026 respectively.

## The numbers

| Metric | RPN Calc | iCrucible |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | **[4.0 (6 ratings)](https://appshunter.io/ios/app/rpn-calc/id285002799/reviews)** | — |
| Number of ratings | **6** | — |
| Positive reviews | 37.9% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 3 months** | Every 5 months |
| Monetization | Free | — |
| Size | 3 MB | 172 MB |
| Requires iOS | **16.0** | 17.2 |
| Devices | **iPhone, iPad, Apple Watch** | iPhone, iPad |
| Age rating | +4 | 4+ |
| Developer | [James Mattis](https://appshunter.io/developer/285002802) | [RIMCS LLC](https://appshunter.io/developer/1695388876) |

## What reviewers say

### RPN Calc

[App page](https://appshunter.io/ios/app/rpn-calc/id285002799)

This app provides a straightforward reverse Polish notation (RPN) calculator experience, inspired by classic HP models. It offers a clean interface with large buttons for quick calculations on iPhone, iPad, and Apple Watch, along with a convenient Today Extension for immediate access.

**Highlights:** Reverse Polish Notation (RPN) input, Clean, simple interface, Large, easy-to-press buttons, iPhone, iPad, and Apple Watch support, Today Extension for quick access

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases:** none


### iCrucible

[App page](https://appshunter.io/ios/app/icrucible/id6468351223)

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Standard | $2.99 | per month |
| Premium | $4.99 | per month |
| Standard | $29.99 | per year |
| Premium | $49.99 | per year |
| 500 Flame Gems | $4.99 | one-time |
| 2,500 Flame Gems | $23.99 | one-time |
| 5,000 Flame Gems | $46.99 | one-time |
| 10,000 Flame Gems | $91.90 | one-time |


## Frequently asked questions

### Is RPN Calc free?

RPN Calc costs $0.99, with no in-app purchases.

### Is iCrucible free?

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

### Do RPN Calc or iCrucible have ads?

Neither RPN Calc nor iCrucible shows ads.

### Which is updated more often, RPN Calc or iCrucible?

RPN Calc ships an update every 3 months, and iCrucible every 5 months. Most recently, RPN Calc was updated on October 24, 2026 and iCrucible on October 27, 2026.

---

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