RGBoard vs Stackis RPN
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
RGBoard
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.
- Customizable LED effects
- Rich sound feedback
- Smart word predictions
- Auto-correct support
- Emoji and Kaomoji support
- Multiple language support
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RGBoard is all about cool stuff. It's a keyboard extension that looks like the iOS keyboard but enhances your typing experience with: – Rich sound feedback. – Endless LED effects and smooth visuals which makes the typing exciting. – Smart word predictions. – Auto correct Support. – Emoji Support. – Kaomoji Support. – Liquid Glass Support. – Many other options which make your life easier... Supperted languages: English - Arabic - French - German - Italian - Russian - Spanish(Mexico) - Filipino(Taglong) - Vietnamese(Telex) - Korean - Filipino Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula
Stackis RPN
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.
- RPN calculation style
- Duodecimal (dozenal) support
- Familiar interface for RPN users
- Simple and pleasant user experience
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This is an RPN calculator in the style of, for instance, old HP models. It will feel familiar if you are used to RPN, otherwise it will probably be a little confusing at first. It's not programmable and it doesn't try to mimic older hardware; it's just meant to be a pleasant calculator for those who prefer to use RPN. Also, if you want to perform calculations in duodecimal (dozenal), this app is for you!
Screenshots
Verdict
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.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
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.
| Parameter | RGBoard | Stackis RPN |
|---|---|---|
| Price | $4.99 | Free — better |
| Rating | 3.7 (17 ratings) | 5.0 (2 ratings) — better |
| Positive reviews | 83.3% of reviews | 100.0% of reviews — better |
| Number of ratings | 17 — better | 2 |
| Update frequency | Every 8 days | Every 4 days — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPod | iPhone, iPod |
| Requires iOS | 15 — better | 17.6 |
| Further details — not scored | ||
| Size | 135 MB | 10 MB |
| Age rating | 4+ | 4+ |
| Developer | Ali Pourhadi | Skimra |
Customer experience
RGBoard
Stackis RPN
In-app purchases
RGBoard
- Monthly Pro Plan$0.991 Month
- Annually Pro Plan7 Days trial$4.991 Year
- Lifetime PremiumFree
- Lifetime Premium$19.99
Stackis RPN
- Advanced Mode$1.99
