RePNCalc vs Calculator 17
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
RePNCalc
This utility app offers a Reverse Polish Notation (RPN) calculator experience for iOS devices. It features customizable key layouts via swipe gestures and long-press options for stack items. External keyboard support is also available.
- Reverse Polish Notation (RPN) input
- Swipe gesture key layout customization
- Long-press stack item options
- External keyboard support
- Full iPad, iPhone, and iPod touch support
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Crunch your numbers with the rpn calculator that fits right along side every other iOS app! Don't get held back by the conventions of traditional, keyboarded calculators that can't update their buttons with new functions without the use of a shift key! Use technology from the future, like swipe gestures to change key layouts or touching and holding a stack item to get a popup granting a range of options. This calculator app uses the alternative method called "reverse polish notation" to provide input for calculations. For the curious, check out http://en.wikipedia.org/wiki/Reverse_Polish_notation for more information. You can now also use external keyboards for input, not just the buttons on screen. Purchasing the full version (in the app) unlocks full functionality. Included is basic functionality (+, -, x, and ÷) and complete support for iPad, iPhone, and iPod touch. It also runs well on Apple Silicon Macs with keyboard support!
Calculator 17
This app offers a user-friendly calculator with basic and scientific modes. Access calculations instantly via a home screen widget and review past computations in a saved history.
- User-friendly interface
- Basic and scientific modes
- Home screen widget
- LiveActivity Standby for iPhone
- Calculation history
- Customizable themes
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Introducing Calculator 17, the ultimate tool for all your math needs on the go! *** - User-Friendly: Calculator 17 makes math feel easy and quick, perfect for both school tasks and daily math jobs. *** - Various Modes: Whether it's basic addition or advanced calculations, we have you covered. Switch between the simple calculator and Scientific mode easily. *** - Instant Access: No more searching for the app. With our homescreen widget and LiveActivity Standby for iPhone, perform calculations directly on your main screen, all while choosing from a variety of fun themes. *** - Never Forget: Your calculations are always saved in our handy history tab. Want to share or copy them? It's just one tap away. Calculator 17 isn’t just another math app. It’s your trusty helper, ready to handle any math challenge. Whether you're a student in need of a school calculator or someone who loves playing with numbers, our calculator is the perfect fit.
Screenshots
Verdict
The clearest difference is in-app purchases: Calculator 17 at none against RePNCalc's 1. Calculator 17 also leads on update cadence (every 4 days vs every 9 months) and ratings volume (990 vs 2). RePNCalc's advantage is rating (5.0 vs 4.6). On price, ads, device support and iOS requirement 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
Both are free to download. RePNCalc sells 1 one-off in-app purchase. Calculator 17 asks for nothing beyond the download.
RePNCalc holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: Calculator 17 has 990 ratings behind it against 2, so its average is the more settled of the two. Written reviews complicate that: 0% of RePNCalc's written reviews are positive against 22% of Calculator 17's, so the app with the better star average is not the one people write more warmly about.
RePNCalc ships an update every 9 months, Calculator 17 every 4 days. The most recent releases landed on November 1, 2026 and November 7, 2026 respectively.
| Parameter | RePNCalc | Calculator 17 |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (2 ratings) — better | 4.6 (990 ratings) |
| Positive reviews | 0.0% of reviews | 21.5% of reviews — better |
| Number of ratings | 2 | 990 — better |
| Update frequency | Every 9 months | Every 4 days — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.0 — better | 16.0 |
| Further details — not scored | ||
| Size | 8 MB | 5 MB |
| Age rating | 4+ | 4+ |
| Developer | Michael Redig | AI APPS SRL |
Customer experience
RePNCalc
Calculator 17
Bugs and requests
RePNCalc
Not enough reviews yet to summarise bugs or requests.
Calculator 17
Reported bugs
3 issues- Widget shows up blank
- Numerical display is cut off
- Significant delay between key presses and display update
Requested features
3 requests- Add landscape mode support
- Improve widget responsiveness
- Increase bracket functionality
In-app purchases
RePNCalc
- Unlock Advanced Functions$0.99
Calculator 17
No in-app purchases









