# GPS OS Grid Reference vs Tomstrails GPS UTM

The clearest difference is rating: Tomstrails GPS UTM at 4.8 against GPS OS Grid Reference's 4.4. Tomstrails GPS UTM also leads on ratings volume (1.6K vs 17) and update cadence (every 6 weeks vs every 3 months). On price, review sentiment, ads and in-app purchases there is nothing between them.

Both are free to download. GPS OS Grid Reference sells 2 in-app purchases, starting at $5.99 per year and Tomstrails GPS UTM sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Tomstrails GPS UTM holds the better App Store score, 4.8 against 4.4. That said, the two scores are not equally well evidenced: Tomstrails GPS UTM has 1.6K ratings behind it against 17, so its average is the more settled of the two. Written reviews complicate that: 90% of GPS OS Grid Reference's written reviews are positive against 84% of Tomstrails GPS UTM's, so the app with the better star average is not the one people write more warmly about.

GPS OS Grid Reference ships an update every 3 months, Tomstrails GPS UTM every 6 weeks. The most recent releases landed on September 22, 2026 and September 25, 2026 respectively.

## The numbers

| Metric | GPS OS Grid Reference | Tomstrails GPS UTM |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.4 (17 ratings)](https://appshunter.io/ios/app/gps-os-grid-reference/id993436655/reviews) | **[4.8 (1.6K ratings)](https://appshunter.io/ios/app/tomstrails-gps-utm/id1004370364/reviews)** |
| Number of ratings | 17 | **1.6K** |
| Positive reviews | **89.9% of reviews** | 83.8% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 6 weeks** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 11 MB | 4 MB |
| Requires iOS | 18.0 | **14.1** |
| Devices | iPhone, Apple Watch | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Tomstrails.com](https://appshunter.io/developer/425642318) | [Tomstrails.com](https://appshunter.io/developer/425642318) |

## What reviewers say

### GPS OS Grid Reference

[App page](https://appshunter.io/ios/app/gps-os-grid-reference/id993436655)

This app accurately pinpoints your location on Ordnance Survey maps for Great Britain and Ireland, even without a phone signal. It offers precise grid references, waypoint creation, and navigation features. The display is designed for clarity in all lighting conditions, and it optimizes battery usage.

**Highlights:** Offline map location, Accurate grid references, Waypoint creation and management, High-contrast display, Battery optimization, Share waypoints

**Features:** Family Sharing, Apple Watch app

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Features | $5.99 | per year |
| Feature Pack - Compass & sharing features. | Free | one-time |

**What reviewers like**

- 👍 Simple and easy to use
- 🎯 Accurate grid references
- 🚀 Fast and quick updates
- 💡 Works without phone signal
- 🗺️ Useful for navigation and backup

**What reviewers complain about**

- 🐛 Blurry satellite maps
- 🧭 Compass not accurate
- 📉 Accuracy dropped recently
- 🗺️ No map data included
- 🚫 Cannot search locations

**Reported bugs**

- Waypoint finder satellite view is blurry
- Compass is not accurate
- Accuracy has dropped recently
- Location services permanently dimmed off (iOS)
- App does not work for users not in England

**Requested features**

- Add map data and search functionality
- Improve satellite map clarity
- Add ability to view location on a map
- Enable navigation from point to point
- Add Apple Watch equivalent app


### Tomstrails GPS UTM

[App page](https://appshunter.io/ios/app/tomstrails-gps-utm/id1004370364)

This app provides precise UTM grid references and displays your location on topographic maps. It works offline, supports various regional datums, and offers multiple coordinate formats for easy sharing and use in other applications.

**Highlights:** Fast and accurate UTM grid reference, Locate position on topographic maps, Works without phone signal, Supports regional datums (e.g., ED50), Multiple coordinate formats (1m, 10m, 100m), Share coordinates with other apps, High contrast display for readability

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Feature Pack | Free | one-time |

**What reviewers like**

- 🚀 Simple and free
- 👍 Works well
- 👍 Easy to use
- 👍 Accurate and reliable
- 👍 Great for hiking and emergencies

**What reviewers complain about**

- 🐛 Doesn't do anything
- 🐛 Coordinates not always accurate
- 💰 Requires payment for some features

**Reported bugs**

- Stopped working after iOS update
- UTM grids were off initially, required setting changes

**Requested features**

- Add support for Morocco coordinate system
- Add option to average readings and hold the result
- Add option to reduce coordinate display to 6 digits for emergency use
- Bring back previous features like degrees/minutes display and ability to edit messages


## Frequently asked questions

### Is GPS OS Grid Reference free?

GPS OS Grid Reference is free to download, with in-app purchases available.

### Is Tomstrails GPS UTM free?

Tomstrails GPS UTM is free to download, with in-app purchases available.

### Which has better reviews, GPS OS Grid Reference or Tomstrails GPS UTM?

Tomstrails GPS UTM is rated higher. GPS OS Grid Reference averages 4.4 out of 5 from 17 ratings, while Tomstrails GPS UTM averages 4.8 from 1.6K ratings.

### Do GPS OS Grid Reference or Tomstrails GPS UTM have ads?

Neither GPS OS Grid Reference nor Tomstrails GPS UTM shows ads.

### Which is updated more often, GPS OS Grid Reference or Tomstrails GPS UTM?

GPS OS Grid Reference ships an update every 3 months, and Tomstrails GPS UTM every 6 weeks. Most recently, GPS OS Grid Reference was updated on September 22, 2026 and Tomstrails GPS UTM on September 25, 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.*