# Neptune vs Electric Field Explorer

The clearest difference is price: Neptune at Free against Electric Field Explorer's $1.99. Neptune also leads on update cadence (every 4 days vs every 2 months) and iOS requirement (15.0 vs 26.0). On ads, in-app purchases and device support there is nothing between them.

Neptune is free to download; Electric Field Explorer costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Neptune ships an update every 4 days, Electric Field Explorer every 2 months. The most recent releases landed on October 25, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | Neptune | Electric Field Explorer |
| --- | --- | --- |
| Price | **Free** | $1.99 |
| Rating | **[5.0 (17 ratings)](https://appshunter.io/ios/app/neptune-navigation-rules/id6756641315/reviews)** | — |
| Number of ratings | **17** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 4 days** | Every 2 months |
| Monetization | Free | — |
| Size | 96 MB | 4 MB |
| Requires iOS | **15.0** | 26.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Brice Brown](https://appshunter.io/developer/1555846025) | [Holger Wiesing](https://appshunter.io/developer/828032203) |

## What reviewers say

### Neptune

[App page](https://appshunter.io/ios/app/neptune-navigation-rules/id6756641315)

Prepare for USCG COLREG and OOD exams with a comprehensive study system. Features AI tutoring, interactive 3D visuals for lights and shapes, and a complete question bank with intelligent test modes and progress tracking.

**Highlights:** AI-powered tutor for rule explanations, Interactive 3D lights and shapes trainer, Official USCG question bank, Verbatim memory trainer, Intelligent exam simulator modes, Advanced progress tracking, Offline study capability

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

**In-app purchases:** none


### Electric Field Explorer

[App page](https://appshunter.io/ios/app/electric-field-explorer/id6757281793)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Neptune free?

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

### Is Electric Field Explorer free?

Electric Field Explorer costs $1.99, with no in-app purchases.

### Do Neptune or Electric Field Explorer have ads?

Neither Neptune nor Electric Field Explorer shows ads.

### Which is updated more often, Neptune or Electric Field Explorer?

Neptune ships an update every 4 days, and Electric Field Explorer every 2 months. Most recently, Neptune was updated on October 25, 2026 and Electric Field Explorer on October 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.*