Comparison

GPS Diagnostic vs Doyle Guides

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

GPS Diagnostic

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
Currently charting
Read full description

KEY FEATURES: - Essential tool for your iPhone & iPad. - Test the GPS module. - Fast GPS lock time. - Precise navigation parameters. - Supplements operation of your navigation apps. - GPS "JumpStart" technology. - If location cannot be determined then it diagnoses why. - Assists you in changing conditions to get a reliable location. - GPS, Galileo, GLONASS, QZSS full support. - Latitude & Longitude, and WGS84 included by default. - In-App Purchase: USNG, MGRS, UTM, OSNG, GEOREF, GARS & 174 Datums (free basic functionality). - **NEW** Smaller footprint (now only 35MBytes) - Free technical and customer support by email. -------------------------------------- OVERVIEW: - Lodestone Chart™ displays all essential GPS satellite information using a chart with only 4 bars. This dramatically simplifies the diagnostic process (Registered Copyright). - GPS "JumpStart" technology may resolve GPS problems with third-party navigation applications that have a frozen location, are slow to respond or are performing inaccurately. - Uses the internal GPS of your iPhone or iPad. - Includes a Speedometer, Altimeter and Compass. - Location and altitude ( best-in-class accuracy and reliability ) - Speed (SOG) and Course (COG). - Heading (i.e. Compass) with ability to turn on and off the manual compass calibration. -------------------------------------- IN-APP PURCHASE (IAP) = "COORDINATES-PRO"   This adds additional coordinate systems and datums to the app to let you accurately work with many paper maps and charts used by civilians, U.S. military and NATO forces for walking, sailing, and flying. The coordinate systems and datums included are: - United States National Grid (USNG) - Military Grid Reference System (MGRS) -Old and New - Universal Transverse Mercator (UTM) - Ordnance Survey National Grid (OSNG) for Great Britain - World Geographic Reference System (GEOREF) - Global Area Reference System (GARS) - 174 Datums (e.g. WGS84, NAD83, NAD27, WGS72, ED50, ED79, OSGB36 etc....). -------------------------------------- REVIEWS: - The developer is a professional software and hardware engineer working in the satellite space industry. He is a yachtmaster and pilot with a passion for navigation and Apple products. - Consistent 5 star reviews, see what users are saying: "Perfect Diagnostic Tool - This is the best app if you need to know the actual status of the internal GPS." "Great app for kick starting navigation apps - This app finds a position every time and then all other nav apps work." "Excellent application - This was a much needed application for iOS devices." “I love the app. It’s been great to have when buying a new phone from eBay to check that the GPS is working. I had to return 3 phones last time before I got one with operational GPS.” "Awesome, over used term but this app is - This app does what other developers said they could not do." -------------------------------------- MORE INFORMATION: - Hardware information - Accuracy of measurements shown for pro users. - Imperial, metric and nautical units. These are the most commonly used and most useful navigation units. All easily changeable from the screen in use. - Does not require internet access and does not use cellular data. - Essential tool for any power user. (e.g. navigators, yachtsmen, pilots, app developers) - Share your location by text message, email etc. The format contains all essential information for improved accuracy. - Works with Garmin Glo. - GPS Diagnostic™ is a professional GPS test and measurement utility for your iPhone and iPad.

About

Doyle Guides

Access comprehensive sailing guides for the southern Caribbean, featuring nautical charts, regulations, services, and points of interest. The app offers an interactive map with user-generated comments and corrections, all free to use. In-app purchases provide access to detailed guide book content.

Highlights
  • Comprehensive sailing guides
  • Nautical charts and navigation
  • Interactive satellite map
  • 3000+ points of interest database
  • User comments and corrections
  • Island-specific content bundles
Features
Read full description

Doyle Guides produces the southern Caribbean's most comprehensive and up-to-date sailing guides, complete with nautical charts and navigational information, details on regulations, customs and immigration, general and technical yacht services, marinas, restaurants, provisioning, shore-based attractions, and more. The Doyle Guides mobile app allows users to search our comprehensive 3000+ point of interest database with results shown based on distance from the user and displayed on an interactive satellite map where users can leave public comments as well as suggest corrections and new points of interest, all free of charge. Subscriptions to guide book content is available on both long and short term basis, as well as bundled by island.

Screenshots

GPS Diagnostic4 screens
Doyle Guides4 screens

Verdict

The call

The clearest difference is price: Doyle Guides at Free against GPS Diagnostic's $2.99. GPS Diagnostic's advantage is rating (4.6 vs 4.3) and review sentiment (78% vs 60%). On update cadence, ads, in-app purchases and monetization model there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Doyle Guides is free to download; GPS Diagnostic costs $2.99 up front. GPS Diagnostic sells 1 one-off in-app purchase and Doyle Guides sells 18 in-app purchases, starting at $9.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

GPS Diagnostic holds the better App Store score, 4.6 against 4.3. That said, the two scores are not equally well evidenced: GPS Diagnostic has 554 ratings behind it against 50, 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 60% of Doyle Guides's.

UpkeepUpdate frequency

GPS Diagnostic ships an update every 3 weeks, Doyle Guides every 5 weeks. The most recent releases landed on October 29, 2026 and October 27, 2026 respectively.

Scorecard6 real differences · 5 level
GPS Diagnostic versus Doyle Guides: the parameters behind the verdict, then further details
ParameterGPS DiagnosticDoyle Guides
Price$2.99Free — better
Rating4.6 (554 ratings) — better4.3 (50 ratings)
Positive reviews78.0% of reviews — better60.0% of reviews
Number of ratings554 — better50
Update frequencyEvery 3 weeks — betterEvery 5 weeks
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
Best chart rank#48 — better—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS8.0 — better16.6
Further details — not scored
Size34 MB52 MB
Age rating4+4+
DeveloperDavid RyallChris Doyle Publishing Limited

Customer experience

GPS Diagnostic

All ratings546 ratings
Positive91.4%
Neutral3.1%
Negative5.5%
Written reviews209 reviews
Positive78.0%
Neutral3.8%
Negative18.2%

Doyle Guides

All ratings50 ratings
Positive80.0%
Neutral8.0%
Negative12.0%
Written reviews10 reviews
Positive60.0%
Neutral10.0%
Negative30.0%

Bugs and requests

GPS Diagnostic

Reported bugs

2 issues
  • Crashes on startup for some users
  • Fails to detect GPS signal on certain devices

Requested features

4 requests
  • 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)

Doyle Guides

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

GPS Diagnostic

One-time1
  • Coordinates-ProFree
18 purchases

Doyle Guides

Subscriptions18
  • Trinidad & Tobago - 1 month3 Days trial$9.991 Month
  • Martinique Sailing Guide3 Days trial$19.991 Month
  • St. Lucia Sailing Guide3 Days trial$19.991 Month
Show 15 more
  • St. Vincent Sailing Guide3 Days trial$19.991 Month
  • Grenada Package - 1 month3 Days trial$19.991 Month
  • Trinidad Tobago Sailing Guide7 Days trial$19.991 Year
  • Martinique Sailing Guide7 Days trial$24.991 Year
  • St. Lucia Sailing Guide7 Days trial$24.991 Year
  • St. Vincent Sailing Guide7 Days trial$24.991 Year
  • Grenada Package - 12 months7 Days trial$24.991 Year
  • Southern Leeward Sailing Guide3 Days trial$24.991 Month
  • Northern Leeward Sailing Guide3 Days trial$24.991 Month
  • Windward Islands Guide3 Days trial$29.991 Month
  • BVI Cruising Guide3 Days trial$29.991 Year
  • Windward Islands Guide7 Days trial$39.991 Year
  • Virgin Islands Cruising Guide3 Days trial$39.991 Year
  • Leeward Islands Sailing Guide3 Days trial$39.991 Month
  • Leeward Islands Sailing Guide7 Days trial$59.991 Year

Questions

Is GPS Diagnostic free?
GPS Diagnostic costs $2.99, and also offers in-app purchases.
Is Doyle Guides free?
Doyle Guides is free to download, with in-app purchases available.
Which has better reviews, GPS Diagnostic or Doyle Guides?
GPS Diagnostic is rated higher. GPS Diagnostic averages 4.6 out of 5 from 554 ratings, while Doyle Guides averages 4.3 from 50 ratings.
Do GPS Diagnostic or Doyle Guides have ads?
Neither GPS Diagnostic nor Doyle Guides shows ads.
Which is updated more often, GPS Diagnostic or Doyle Guides?
GPS Diagnostic ships an update every 3 weeks, and Doyle Guides every 5 weeks. Most recently, GPS Diagnostic was updated on October 29, 2026 and Doyle Guides on October 27, 2026.

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