# Celestial Nav vs Rule Master

The clearest difference is price: Celestial Nav at Free against Rule Master's $9.99. Celestial Nav also leads on review sentiment (64% vs 43%) and update cadence (every 3 weeks vs every 3 months). Rule Master's advantage is rating (4.8 vs 4.3) and in-app purchases (none vs 6). On ads, monetization model and iOS requirement there is nothing between them.

Celestial Nav is free to download; Rule Master costs $9.99 up front. Celestial Nav sells 6 in-app purchases, starting at $1.99 per month. Rule Master asks for nothing beyond the download.

Rule Master holds the better App Store score, 4.8 against 4.3. That said, the two scores are not equally well evidenced: Rule Master has 292 ratings behind it against 10, so its average is the more settled of the two. Written reviews complicate that: 64% of Celestial Nav's written reviews are positive against 43% of Rule Master's, so the app with the better star average is not the one people write more warmly about.

Celestial Nav ships an update every 3 weeks, Rule Master every 3 months. The most recent releases landed on October 1, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | Celestial Nav | Rule Master |
| --- | --- | --- |
| Price | **Free** | $9.99 |
| Rating | [4.3 (10 ratings)](https://appshunter.io/ios/app/celestial-nav/id1569880598/reviews) | **[4.8 (292 ratings)](https://appshunter.io/ios/app/rule-master/id1617543595/reviews)** |
| Number of ratings | 10 | **292** |
| Positive reviews | **64.3% of reviews** | 42.9% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 3 months |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Best chart rank | — | **#23** |
| Size | 20 MB | 13 MB |
| Requires iOS | **15.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Skytip LLC](https://appshunter.io/developer/1569880600) | [Universal Queue LLC](https://appshunter.io/developer/1577058225) |

## What reviewers say

### Celestial Nav

[App page](https://appshunter.io/ios/app/celestial-nav/id1569880598)

This app provides tools for celestial navigation, offering computations for celestial bodies and sight reductions. It includes an offline perpetual almanac and allows for quick capture of observation data for accurate course adjustments.

**Highlights:** Celestial navigational computations, Offline perpetual almanac, Quick celestial observation data capture, High accuracy sight reductions, Sight planning and reduction tools, Celestial fix computations

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

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PRO Version | $1.99 | per month |
| PRO Version | $7.99 | per 6 months |
| PRO Version | $9.99 | per year |
| 7 Day Trial License | $0.99 | one-time |
| 30 Day Trial License | $2.99 | one-time |
| PRO Version Lifetime | $24.99 | one-time |


### Rule Master

[App page](https://appshunter.io/ios/app/rule-master/id1617543595)

**Currently charting:** #23 Top Paid · Navigation (US App Store)

Master maritime navigation rules with this comprehensive quiz app. It offers extensive question banks, custom filters, and detailed progress tracking for both new and experienced sailors. Generate custom exams and access a digital handbook for efficient learning and exam preparation.

**Highlights:** 10,000+ question-answer combinations, Custom question filters, Fill-in-the-blank questions, Offline capability, Exam PDF generation, Digital Navigation Rules handbook, Progress tracking and statistics

**Features:** Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 👍 User friendly and easy to navigate
- 📚 Great information for studying and review
- 💯 Helpful for exam preparation and confidence
- ✨ Beautifully designed and functional app
- ✅ Worth a download

**What reviewers complain about**

- 💰 Free apps are just as good
- 🐛 Questions disappear off the screen
- 🤏 Diagrams are too small to see details
- ❓ Incomplete questions with missing text
- ⚠️ Some answers are not 100% accurate

**Reported bugs**

- Questions disappear off the bottom of the screen
- Diagrams are too small to identify vessels
- Some questions have character limits over the margin
- App doesn't display quiz and verbatim in a usable manner
- Incomplete questions showing three dots (...)

**Requested features**

- Link relevant COLREG rule when answering correctly and incorrectly
- Expand subjects to include chemistry or history
- Improvements in tracking missed questions for training
- Display full question text when it's cut off


## Frequently asked questions

### Is Celestial Nav free?

Celestial Nav is free to download, with in-app purchases available.

### Is Rule Master free?

Rule Master costs $9.99, with no in-app purchases.

### Which has better reviews, Celestial Nav or Rule Master?

Rule Master is rated higher. Celestial Nav averages 4.3 out of 5 from 10 ratings, while Rule Master averages 4.8 from 292 ratings.

### Do Celestial Nav or Rule Master have ads?

Neither Celestial Nav nor Rule Master shows ads.

### Which is updated more often, Celestial Nav or Rule Master?

Celestial Nav ships an update every 3 weeks, and Rule Master every 3 months. Most recently, Celestial Nav was updated on October 1, 2026 and Rule Master on October 11, 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.*