# RGBoard vs Stackis RPN

The clearest difference is price: Stackis RPN at Free against RGBoard's $4.99. Stackis RPN also leads on rating (5.0 vs 3.7) and review sentiment (100% vs 83%). RGBoard's advantage is ratings volume (17 vs 2) and iOS requirement (15 vs 17.6). On ads, in-app purchases and device support there is nothing between them.

Stackis RPN is free to download; RGBoard costs $4.99 up front. RGBoard sells 4 in-app purchases, starting at $0.99 per month and Stackis RPN sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Stackis RPN holds the better App Store score, 5.0 against 3.7. That said, the two scores are not equally well evidenced: RGBoard has 17 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 83% of RGBoard's written reviews are positive against 100% of Stackis RPN's.

RGBoard ships an update every 8 days, Stackis RPN every 4 days. The most recent releases landed on September 23, 2026 and June 2, 2026 respectively.

## The numbers

| Metric | RGBoard | Stackis RPN |
| --- | --- | --- |
| Price | $4.99 | **Free** |
| Rating | [3.7 (17 ratings)](https://appshunter.io/ios/app/rgboard-animated-keyboard/id6741393117/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/stackis-rpn/id6752929114/reviews)** |
| Number of ratings | **17** | 2 |
| Positive reviews | 83.3% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 8 days | **Every 4 days** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 135 MB | 10 MB |
| Requires iOS | **15** | 17.6 |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Ali Pourhadi](https://appshunter.io/developer/1790080539) | [Skimra](https://appshunter.io/developer/403502071) |

## What reviewers say

### RGBoard

[App page](https://appshunter.io/ios/app/rgboard-animated-keyboard/id6741393117)

This keyboard extension offers a visually engaging typing experience with customizable LED effects and sound feedback. It includes smart word predictions, auto-correction, and support for emojis and kaomojis to enhance your typing efficiency and enjoyment.

**Highlights:** Customizable LED effects, Rich sound feedback, Smart word predictions, Auto-correct support, Emoji and Kaomoji support, Multiple language support

**Features:** Family Sharing

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Pro Plan | $0.99 | per month |
| Annually Pro Plan | $4.99 | per year |
| Lifetime Premium | Free | one-time |
| Lifetime Premium | $19.99 | one-time |


### 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 |


## Frequently asked questions

### Is RGBoard free?

RGBoard costs $4.99, and also offers in-app purchases.

### Is Stackis RPN free?

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

### Which has better reviews, RGBoard or Stackis RPN?

Stackis RPN is rated higher. RGBoard averages 3.7 out of 5 from 17 ratings, while Stackis RPN averages 5.0 from 2 ratings.

### Do RGBoard or Stackis RPN have ads?

Neither RGBoard nor Stackis RPN shows ads.

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

RGBoard ships an update every 8 days, and Stackis RPN every 4 days. Most recently, RGBoard was updated on September 23, 2026 and Stackis RPN on June 2, 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.*