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GPS Diagnostic: Satellite Test

by David Ryall

  • Navigation
  • Paid
  • Zombie
  • Small & simple · 89
View on the App Store
Rating
4.7
553 ratings · US storefront
Top 57%among 116 Navigation apps
Last update
Jun 25, 2020
Version 3.6
Size
36 MB
Category
Navigation
Tracked since
Oct 9, 2026

Estimated revenue

A model estimate with a likely range, not a reported figure.

No estimate. Apps outside the grossing charts, and some countries, have no reliable rank-to-revenue curve, so we show nothing rather than a guess.

How this estimate is made

Rank: we take the app's best Top Grossing rank on the latest chart day. Category ranks are converted into an equivalent overall rank, because a #10 in Finance earns far less than a #10 overall.

Curve: that equivalent rank is read off a rank-to-revenue curve anchored on public company revenue and market-data reports for the US iPhone App Store.

Country: the curve is scaled per country (Japan is roughly a third of the US, Türkiye under 1%). Where we have no scale, such as China, there is no estimate.

Range: the likely range widens with country, category and chart depth. It is a plausible span, not a statistical confidence interval.

Not included: ads, payments outside the App Store, and any difference between gross sales and what the developer keeps. Low confidence means indirect data; medium means several independent sources agree.

Full method

Screenshots

As shown on the App Store listing.

About this app

Text from the App Store listing.

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.

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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.

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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....).

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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."
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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.

What’s new

Release notes for the latest version, as written by the developer.

v3.6
Original · root

80% reduction in file size to 35MB. Full support for latest iPad Pro 4th Generation.

Rank history

Daily position in the Poland charts. #1 is at the top.

Best rank
#6
Current rank
#6
Days charting
7 of 7

On the charts today

Small & simple score

How realistic it is for a small team to build something like this.

89/100

Small & simple

  • Developer size70% · 25

    Developer: 2 apps on the charts

  • Audience size80% · 20

    Ratings: 553

  • App size100% · 10

    Size: 36 MB

  • Price model100% · 15

    Price model: paid

  • Demand proof100% · 30

    Best rank #1, 106 countries

An indicator, not a fact. We can't see team size. Calculated Oct 25, 2026 · method i2

How the score works

Version history

  • 3.6LatestReleased Jun 25, 2020