# Stackis RPN vs RPN

The clearest difference is in-app purchases: RPN at none against Stackis RPN's 1. RPN also leads on iOS requirement (15.6 vs 17.6). Stackis RPN's advantage is update cadence (every 4 days vs every 6 months). On price, ads and device support there is nothing between them.

Both are free to download. Stackis RPN sells 1 one-off in-app purchase. RPN asks for nothing beyond the download.

Stackis RPN ships an update every 4 days, RPN every 6 months. Both last shipped on October 12, 2026.

## The numbers

| Metric | Stackis RPN | RPN |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/stackis-rpn/id6752929114/reviews)** | — |
| Number of ratings | **2** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 4 days** | Every 6 months |
| Monetization | Free | — |
| Size | 10 MB | 1 MB |
| Requires iOS | 17.6 | **15.6** |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Skimra](https://appshunter.io/developer/403502071) | [Joachim Seland Graff](https://appshunter.io/developer/1845679029) |

## What reviewers say

### Stackis RPN

[App page](https://appshunter.io/ios/app/stackis-rpn/id6752929114)

A calculator designed for users who prefer Reverse Polish Notation (RPN). It offers a familiar interface for RPN users and includes support for duodecimal calculations.

**Highlights:** RPN calculation style, Duodecimal (dozenal) support, Familiar interface for RPN users, Simple and pleasant user experience

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Advanced Mode | $1.99 | one-time |


### RPN

[App page](https://appshunter.io/ios/app/rpn/id6754224532)

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

**In-app purchases:** none


## Frequently asked questions

### Is Stackis RPN free?

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

### Is RPN free?

RPN is free to download, with no in-app purchases.

### Do Stackis RPN or RPN have ads?

Neither Stackis RPN nor RPN shows ads.

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

Stackis RPN ships an update every 4 days, and RPN every 6 months. Most recently, Stackis RPN was updated on October 12, 2026 and RPN on October 12, 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.*