# Tomstrails GPS Duo — Worldwide Coordinate Formats

> Displays location in multiple worldwide coordinate and grid formats. (iPhone/iPad app by Tomstrails.com.)

- Source: https://appshunter.io/ios/app/tomstrails-gps-duo/id425642315 (this page in markdown: same URL + `.md`)
- Developer: [Tomstrails.com](https://appshunter.io/developer/425642318)
- Category: Navigation, Travel
- Price: Free
- Rating: 4.60/5 from 145 App Store ratings · 91 written reviews indexed
- Age rating: 4+
- Requires: iOS 11.0 · 10 MB
- Languages: American English
- Released: 2011-03-20
- Data updated: 2026-08-26
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/tomstrails-gps-duo/id425642315/reviews.md

## What is Tomstrails GPS Duo?

Provides a clear and concise display of your position in map coordinates used widely around the world.

GRID FORMATS
• British Grid, used by Ordnance Survey in Great Britain.
• Irish Grid, used by Ordnance Survey in Ireland.
• MGRS (Military Grid Reference System)
• UTM used worldwide with both the WGS-84 datum and ED50 in parts of Europe.
• Latitude & Longitude in decimal and sexagesimal notation.

EXTENDED BATTERY LIFE
Tomstrails GPS optimizes the frequency of position updates depending on battery charge and speed of travel to make sure you can always make a call at the end of the day, great for multi-day trips. The GPS is never enabled when the app is in background.

CRISP, CLEAR DISPLAY
A clear, high contrast display ensures you can read the position quickly in any light conditions. Simultaneous grid formats allows emergency services to coordinate ground and aerial support.

## Key features

- Multiple grid formats (British, Irish, MGRS, UTM)
- Latitude & Longitude display
- Optimized battery life
- High-contrast display
- Simultaneous grid format display

## What do users think of Tomstrails GPS Duo?

Overall sentiment: positive

**Pros**

- 👍 Simple and intuitive user interface
- 🎯 Accurate GPS coordinates and location tracking
- ⚡ Fast performance and quick GPS fixes
- 🔋 Low battery consumption
- 📍 Multiple coordinate system support (Lat/Long, UTM, MGRS, OS Grid)
- 📤 Easy location sharing via text, email, and social media
- 🔤 Large, easy-to-read display
- 🚀 Minimal bloatware and focused functionality
- 🌍 Works without phone signal or internet connection
- 🎨 Clean, uncluttered design
- ⏱️ Reliable for emergency situations and SAR operations
- 📱 Apple Watch support available

**Cons**

- 🧭 Azimuth/compass readings reported as ~30 degrees off
- 📍 Limited coordinate system options (missing NAD83)
- 🔄 Recent UI changes made coordinate systems less accessible
- ⌚ Apple Watch functionality limited or unavailable
- 🌙 No dark mode or night navigation support
- 📋 Limited data export and recording capabilities
- 🐛 App crashes on launch in some locations/devices
- 📱 iPad GPS support not recognized
- 🔗 Lost Google Maps linking functionality in recent updates
- 🎯 Compass reading source not clearly labeled (magnetic vs true)

**Commonly reported bugs**

- App crashes on launch in certain locations
- iPad GPS not recognized despite device capability
- Azimuth readings approximately 30 degrees inaccurate
- Google Maps linking feature broken in recent updates
- Inconsistent performance with older iOS versions
- Guernsey location not supported, causing crashes

**Most requested features**

- Apple Watch full compatibility
- Dark mode or inverted colors for night navigation
- Portrait orientation mode
- 10-figure grid references instead of 8-figure
- NAD83 coordinate system support
- Ability to record and save multiple coordinate readings
- Date and time copying to clipboard
- Custom grid support for surveyors
- Stakeout functionality (direction and distance to target coordinates)
- Negative elevation support
- Comma-separated coordinate format for third-party app integration
- Last 5 coordinates history
- Direct OS grid reference capture and sharing
- Map datum selection option
- Automatic real-time coordinate updates as you move
- Built-in compass feature
- Portrait mode support

## Recent user reviews (10 of 91)

All indexed reviews: https://appshunter.io/ios/app/tomstrails-gps-duo/id425642315/reviews.md

### 5/5 — Hikers review.

*2026-08-06*

Fantastic I love its readability and the developers obvious awareness of the difficulties of field navigation for ordinary people.

### 5/5 — Lat/long and grid 😍

*2026-04-01*

Mag to grid

### 5/5 — Mon meilleur choix enfin

*2026-03-29*

Super app.!

### 5/5 — Luv it

*2026-01-26, version 3.0.0*

Terrific and simple to use app

### 5/5 — Excellent

*2025-10-24*

Brilliant app. 
Simple accurate,  and no fuss

### 5/5 — Very good

*2025-08-31, version 3.0.0*

Fast and easy to use.

### 5/5 — NAD83

*2024-10-14*

Would be nice if included NAD83

### 5/5 — Best App

*2024-08-15, version 3.0.0*

Simple and works as it should.

### 5/5 — The best location app

*2024-02-09*

Very simple to set up and clear coordinates. You can customise the share location feature to send one or two coordinates system locations e.g. UK Ordinance Survey and GPS Latitude and Longitude. Better that what 3 words as it is much easier to tell emergency services your location as numbers are very simple to understand even over a poor phone connection

**Developer response:** Thank you Mark.

### 5/5 — USEFUL APP

*2024-01-08, version 3.0.0*

To put it briefly, it is unique and practical

## Frequently asked questions about Tomstrails GPS Duo

### What does Tomstrails GPS Duo do?

Tomstrails GPS Duo displays your current location using a variety of widely used coordinate systems and grid formats. It supports British Grid, Irish Grid, MGRS, UTM, and Latitude & Longitude in both decimal and sexagesimal notation.

### What are the key features of this app?

Key features include support for multiple global grid formats, a clear high-contrast display for readability in any light, and optimized battery life that adjusts position update frequency. It also allows for simultaneous display of different grid formats.

### Is Tomstrails GPS Duo free to use?

Yes, the application is available for free. It does not have in-app purchases or advertisements, meaning you can use all its features without any cost.

### Who would benefit from using this app?

This app is ideal for anyone who needs precise location information in various formats, such as hikers, outdoor adventurers, travelers, and emergency responders. It's particularly useful for coordinating ground and aerial support.

### How does the app help with battery life?

The app optimizes battery life by intelligently adjusting the frequency of GPS position updates based on your speed of travel and current battery charge. The GPS is also deactivated when the app is running in the background.

## Version history (last 5 releases)

### 3.0.0 — 2019-12-27

Updated to support recent devices and iOS 13.

### 2.2 — 2015-07-29

Custom Share format including grid(s), elevation, time and Google Maps.

If you love our app., please take a moment to update your Appstore review. Your great reviews enable us to keep making free updates.

### 2.1 — 2015-05-13

Apple Watch supported added.

If you love our app., please take a moment to update your Appstore review. Your great reviews enable us to keep making free updates.

### 2.0.3 — 2015-04-24

A new fresh appearance incorporating magnetic heading and additional sharing options.

Dual display provides simultaneous grid formats. Enable this feature in Settings.

If you love our app., please take a moment to update your Appstore review. Your great reviews enable us to keep making free updates.

### 2.0.2 — 2015-04-09

A new fresh appearance incorporating magnetic heading and additional sharing options.

Sexagesimal notation now includes degrees, minutes and seconds symbols. The resolution of sexagesimal coordinates has been increased.

If you love our app., please take a moment to update your Appstore review. Your great reviews enable us to keep making free updates.

## Apps similar to Tomstrails GPS Duo

| App | Rating | Price | Category |
| --- | --- | --- | --- |
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## More apps by Tomstrails.com

- [GPS OS Grid Reference](https://appshunter.io/ios/app/gps-os-grid-reference/id993436655)
- [Tomstrails GPS UTM](https://appshunter.io/ios/app/tomstrails-gps-utm/id1004370364)
- [Cotswold Walks](https://appshunter.io/ios/app/cotswold-walks/id1279020717)
- [Cornwall Walks](https://appshunter.io/ios/app/cornwall-walks/id1411191127)
- [Lake District Walks](https://appshunter.io/ios/app/lake-district-walks/id1463266357)

All apps by Tomstrails.com: https://appshunter.io/developer/425642318

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-26.*