# RPN vs Skipper Science App

The clearest difference is price: Skipper Science App at Free against RPN's $2.99. Skipper Science App also leads on rating (5.0 vs 4.3) and update cadence (every 3 weeks vs every 2 months). RPN's advantage is ratings volume (10 vs 1) and iOS requirement (12.0 vs 15.6). On ads, in-app purchases and device support there is nothing between them.

Skipper Science App is free to download; RPN costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Skipper Science App holds the better App Store score, 5.0 against 4.3. That said, the two scores are not equally well evidenced: RPN has 10 ratings behind it against 1, so its average is the more settled of the two.

RPN ships an update every 2 months, Skipper Science App every 3 weeks. The most recent releases landed on November 3, 2026 and November 8, 2026 respectively.

## The numbers

| Metric | RPN | Skipper Science App |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | [4.3 (10 ratings)](https://appshunter.io/ios/app/rpn-25-ce/id1529311398/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/skipper-science-app/id6504762932/reviews)** |
| Number of ratings | **10** | 1 |
| Positive reviews | 80.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 3 weeks** |
| Monetization | Paid | **Free** |
| Size | 28 MB | 154 MB |
| Requires iOS | **12.0** | 15.6 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 17+ |
| Developer | [CuVee Software](https://appshunter.io/developer/424873503) | [Aleut Community of St. Paul Island Tribal Government](https://appshunter.io/developer/1329178887) |

## What reviewers say

### RPN

[App page](https://appshunter.io/ios/app/rpn-25-ce/id1529311398)

This app is a photo-realistic simulation of the classic HP-25 scientific calculator. It offers advanced programming features, a vast function library, and modern enhancements for enhanced usability on iOS devices.

**Highlights:** Photo-realistic simulation, Programmable (99/999 steps), 15 user-defined function keys, 100 symbolic labels, 100 visible registers, Program library with 150+ programs, Over 270 functions

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

**In-app purchases:** none


### Skipper Science App

[App page](https://appshunter.io/ios/app/skipper-science-app/id6504762932)

This app allows fishermen to easily report valuable marine data from their phones while at sea. It supports structured data collection on environmental and fisheries priorities, even without internet access. Join a community advocating for healthy fisheries.

**Highlights:** Report jellyfish and algae blooms, Log fish stomach contents, Record entanglements and marine debris, Track sea surface temperature, Document marine mammal interactions, Offline data logging, Structured data collection forms

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

**In-app purchases:** none


## Frequently asked questions

### Is RPN free?

RPN costs $2.99, with no in-app purchases.

### Is Skipper Science App free?

Skipper Science App is free to download, with no in-app purchases.

### Which has better reviews, RPN or Skipper Science App?

Skipper Science App is rated higher. RPN averages 4.3 out of 5 from 10 ratings, while Skipper Science App averages 5.0 from 1 ratings.

### Do RPN or Skipper Science App have ads?

Neither RPN nor Skipper Science App shows ads.

### Which is updated more often, RPN or Skipper Science App?

RPN ships an update every 2 months, and Skipper Science App every 3 weeks. Most recently, RPN was updated on November 3, 2026 and Skipper Science App on November 8, 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.*