# RPN 28x Calc vs RPN

The clearest difference is price: RPN at Free against RPN 28x Calc's $6.99. RPN 28x Calc's advantage is update cadence (every 2 months vs every 7 months) and rating (5.0 vs 4.7). On review sentiment, ads, in-app purchases and device support there is nothing between them.

RPN is free to download; RPN 28x Calc costs $6.99 up front. Neither carries in-app purchases, so what you see is what you pay.

RPN 28x Calc holds the better App Store score, 5.0 against 4.7. Both are backed by a comparable volume of ratings — 34 and 11 respectively. Written reviews complicate that: 97% of RPN 28x Calc's written reviews are positive against 100% of RPN's, so the app with the better star average is not the one people write more warmly about.

RPN 28x Calc ships an update every 2 months, RPN every 7 months. The most recent releases landed on September 13, 2026 and August 26, 2026 respectively.

## The numbers

| Metric | RPN 28x Calc | RPN |
| --- | --- | --- |
| Price | $6.99 | **Free** |
| Rating | **[5.0 (34 ratings)](https://appshunter.io/ios/app/rpn-28x-calc/id529927583/reviews)** | [4.7 (11 ratings)](https://appshunter.io/ios/app/rpn-70-sd/id738422213/reviews) |
| Number of ratings | **34** | 11 |
| Positive reviews | 96.7% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 7 months |
| Monetization | Paid | **Free** |
| Size | 3 MB | 17 MB |
| Requires iOS | 12.4 | **12.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [tredje design](https://appshunter.io/developer/495557933) | [CuVee Software](https://appshunter.io/developer/424873503) |

## What reviewers say

### RPN 28x Calc

[App page](https://appshunter.io/ios/app/rpn-28x-calc/id529927583)

A programmable scientific calculator offering a classic aesthetic with modern functionality. It features a dynamic stack display, customizable buttons, and support for multiple data types, making complex calculations intuitive and accessible.

**Highlights:** Reverse Polish Notation (RPN) input, Dynamic stack display with scrolling, Customizable buttons and programming, Support for multiple data types (real, complex, binary, lists, etc.), 147 scientific units and physical constants, Interactive program debugging, Units and log viewers

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

**In-app purchases:** none


### RPN

[App page](https://appshunter.io/ios/app/rpn-70-sd/id738422213)

This app is a faithful simulation of a rare 1974 financial calculator, offering all its original functions with enhanced features like more memory registers and a visual stack display. It's designed for users who appreciate vintage technology and need precise financial calculations.

**Highlights:** Photo-realistic vintage calculator design, Full HP-70 function simulation, Animated keys with sound, Enhanced stack and memory register view, Cut/copy/paste display value, Input parameter visual indicators

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

**In-app purchases:** none


## Frequently asked questions

### Is RPN 28x Calc free?

RPN 28x Calc costs $6.99, with no in-app purchases.

### Is RPN free?

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

### Which has better reviews, RPN 28x Calc or RPN?

RPN 28x Calc is rated higher. RPN 28x Calc averages 5.0 out of 5 from 34 ratings, while RPN averages 4.7 from 11 ratings.

### Do RPN 28x Calc or RPN have ads?

Neither RPN 28x Calc nor RPN shows ads.

### Which is updated more often, RPN 28x Calc or RPN?

RPN 28x Calc ships an update every 2 months, and RPN every 7 months. Most recently, RPN 28x Calc was updated on September 13, 2026 and RPN on August 26, 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.*