# WP 31s vs RPN

The clearest difference is price: WP 31s at Free against RPN's $1.99. RPN's advantage is update cadence (every 3 months vs every 10 months). On rating, review sentiment, ratings volume and ads there is nothing between them.

WP 31s is free to download; RPN costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

On the App Store both sit at effectively the same score — 4.9 for WP 31s against 5.0 for RPN. Both are backed by a comparable volume of ratings — 15 and 8 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

WP 31s ships an update every 10 months, RPN every 3 months. The most recent releases landed on June 11, 2026 and September 6, 2026 respectively.

## The numbers

| Metric | WP 31s | RPN |
| --- | --- | --- |
| Price | **Free** | $1.99 |
| Rating | [4.9 (15 ratings)](https://appshunter.io/ios/app/wp-31s/id973621300/reviews) | **[5.0 (8 ratings)](https://appshunter.io/ios/app/rpn-55-sd/id1469907917/reviews)** |
| Number of ratings | **15** | 8 |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 10 months | **Every 3 months** |
| Monetization | **Free** | Paid |
| Size | 16 MB | 17 MB |
| Requires iOS | 12.0 | 12.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Pascal Meheut](https://appshunter.io/developer/620255097) | [CuVee Software](https://appshunter.io/developer/424873503) |

## What reviewers say

### WP 31s

[App page](https://appshunter.io/ios/app/wp-31s/id973621300)

This app emulates a classic RPN scientific calculator, offering a rich function set for daily use with a simplified interface. It's based on the more complex WP 34s but is designed for easier operation.

**Highlights:** RPN scientific calculator emulation, Rich function set, Simplified, less cluttered keyboard, Based on WP 34s, Available on iOS

**Features:** macOS Compatibility

**In-app purchases:** none


### RPN

[App page](https://appshunter.io/ios/app/rpn-55-sd/id1469907917)

This app is a photo-realistic simulation of a classic Hewlett-Packard programmable scientific calculator from the 1970s. It includes a 100-hour digital timer, clock functions, and original HP programs.

**Highlights:** Photo-realistic look-and-feel, Programmable with conditional branching, 100-hr timer and 12/24-hr clock, Original HP programs built-in, Extended features for enhanced usability, Sharing via email, AirDrop, and more

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is WP 31s free?

WP 31s is free to download, with no in-app purchases.

### Is RPN free?

RPN costs $1.99, with no in-app purchases.

### Which has better reviews, WP 31s or RPN?

RPN is rated higher. WP 31s averages 4.9 out of 5 from 15 ratings, while RPN averages 5.0 from 8 ratings.

### Do WP 31s or RPN have ads?

Neither WP 31s nor RPN shows ads.

### Which is updated more often, WP 31s or RPN?

WP 31s ships an update every 10 months, and RPN every 3 months. Most recently, WP 31s was updated on June 11, 2026 and RPN on September 6, 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.*