# GPS Diagnostic vs Celestial Nav

The clearest difference is price: Celestial Nav at Free against GPS Diagnostic's $2.99. GPS Diagnostic's advantage is rating (4.7 vs 4.3) and ratings volume (553 vs 10). On update cadence, ads, in-app purchases and monetization model there is nothing between them.

Celestial Nav is free to download; GPS Diagnostic costs $2.99 up front. GPS Diagnostic sells 1 one-off in-app purchase and Celestial Nav sells 6 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

GPS Diagnostic holds the better App Store score, 4.7 against 4.3. That said, the two scores are not equally well evidenced: GPS Diagnostic has 553 ratings behind it against 10, so its average is the more settled of the two. Written reviews point the same way: 78% of GPS Diagnostic's written reviews are positive against 64% of Celestial Nav's.

Both ship on a similar rhythm, roughly every 3 weeks. The most recent releases landed on October 22, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | GPS Diagnostic | Celestial Nav |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | **[4.7 (553 ratings)](https://appshunter.io/ios/app/gps-diagnostic-satellite-test/id1020967894/reviews)** | [4.3 (10 ratings)](https://appshunter.io/ios/app/celestial-nav/id1569880598/reviews) |
| Number of ratings | **553** | 10 |
| Positive reviews | **78.0% of reviews** | 64.3% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | Every 3 weeks |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Best chart rank | **#128** | — |
| Size | 34 MB | 20 MB |
| Requires iOS | **8.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [David Ryall](https://appshunter.io/developer/925576172) | [Skytip LLC](https://appshunter.io/developer/1569880600) |

## What reviewers say

### GPS Diagnostic

[App page](https://appshunter.io/ios/app/gps-diagnostic-satellite-test/id1020967894)

**Currently charting:** #128 Top Paid · Navigation (US App Store)

This app tests your device's GPS module, providing precise navigation parameters and diagnosing location issues. It supports multiple satellite systems and offers advanced coordinate conversions through an in-app purchase.

**Highlights:** Test GPS module, Fast GPS lock time, Precise navigation parameters, GPS "JumpStart" technology, Full satellite system support, Additional coordinate systems (IAP)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Coordinates-Pro | Free | one-time |

**What reviewers like**

- 👍 Helpful diagnostic tool
- 🚀 Provides detailed GPS information
- 🔧 Useful for troubleshooting GPS issues
- 💡 Allows resetting GPS receiver
- 👍 Clean and intuitive interface

**What reviewers complain about**

- 🐛 Compatibility issues with newer iOS versions
- 🔍 Limited satellite data display (only 4 bars)
- 📝 Email support button not working
- 🔍 Lacks detailed information on satellite types

**Reported bugs**

- Crashes on startup for some users
- Fails to detect GPS signal on certain devices

**Requested features**

- Display number of satellites in view and locked
- Expand satellite signal strength graph to show more satellites
- Add support for landscape mode
- Provide more detailed GPS information (e.g., HDOP, VDOP)


### 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 |


## Frequently asked questions

### Is GPS Diagnostic free?

GPS Diagnostic costs $2.99, and also offers in-app purchases.

### Is Celestial Nav free?

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

### Which has better reviews, GPS Diagnostic or Celestial Nav?

GPS Diagnostic is rated higher. GPS Diagnostic averages 4.7 out of 5 from 553 ratings, while Celestial Nav averages 4.3 from 10 ratings.

### Do GPS Diagnostic or Celestial Nav have ads?

Neither GPS Diagnostic nor Celestial Nav shows ads.

### Which is updated more often, GPS Diagnostic or Celestial Nav?

GPS Diagnostic ships an update every 3 weeks, and Celestial Nav every 3 weeks. Most recently, GPS Diagnostic was updated on October 22, 2026 and Celestial Nav on October 17, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*