App Overview

GPS Diagnostic: Satellite Test icon

GPS Diagnostic: Satellite Test

David Ryall · Navigation

KEY FEATURES:

$2.99 · In-app purchases

PRICE
$2.99
In-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
4.6
551 ratings · Top 15%

Evidence scope: No current overall US chart position is available. Category-chart positions shown in discovery are a separate scope. Revenue is a directional model estimate, not verified earnings.

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What's included17 files

A product spec, phased build plan, differentiation notes, and screen references.

  • START_HERE
  • AGENTS
  • EVIDENCE
  • SPEC
  • BUILD_PLAN
  • DIFFERENTIATION
  • skills/
  • screens/
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Illustrative example: an invoice app for independent contractors. Your kit is tailored to the app you choose; this is not its generated content.

Feature spec

Goal: Send a clear invoice after finishing a job.

  • Add a client, line items, a due date, and payment instructions.
  • Preview the total before exporting a PDF.
  • Keep an editable draft if export fails.

Screen plan

Invoice editor: Client at the top, editable line items in the middle, total and preview action at the bottom.

States: Empty draft, validation errors beside each field, exporting, and a retry action that preserves the draft.

Differentiate and validate

Hypothesis: Contractors need faster repeat invoices more than more templates.

First experiment: Test duplicating a previous job with five contractors. Watch where they hesitate before expanding the feature set.

The full kit adds a phased build plan, evidence notes, tool prompts, and implementation guidance. It is a plan for your coding agent, not a finished app.

Usage: Mechanics are fair game; never reuse the original name, branding, assets, or verbatim copy.

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Quick prompt

> SELECT BUILD PLATFORM:

Good fit for mobile-first iOS and Android prototypes with managed app scaffolding.

// RORK SYSTEM PROMPT
Rork plan preview for GPS Diagnostic: Satellite Test: map the core Navigation workflow, choose the smallest differentiated feature set, define the data and monetization boundaries, then prototype the riskiest user journey first.
            

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Opportunities

AI-GENERATED OPPORTUNITY HYPOTHESES

These are generated suggestions, not verified review quotations. Check current App Store reviews and speak with users before treating a possible gap as a requirement.

Hypothesis 1

Include more detailed satellite information and diagnostics.

Assumption to check: Limited functionality for advanced GPS diagnostics

Validate with people who use this workflow before building.

Hypothesis 2

Provide clear explanations and benefits of each premium feature.

Assumption to check: In-app purchases may confuse users

Validate with people who use this workflow before building.

Hypothesis 3

Add a support feature for users to report issues or request features.

Assumption to check: Lack of user support or feedback options

Validate with people who use this workflow before building.

Hypothesis 4

Improve the update frequency to enhance app functionality and user trust.

Assumption to check: Infrequent updates

Validate with people who use this workflow before building.

App evidence

Original App Store material. Ratings and screenshots describe the existing app, not proof of demand for your version.

App Store 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.

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Screenshots

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Build scope

Plan a focused first version with your coding agent. These are planning assumptions, not a delivery guarantee.

Define the first version

Choose one audience and one core workflow. Use the kit to agree on its screens, data, and acceptance criteria before building.

Set boundaries

Decide which secondary features, integrations, and platform support can wait. Your version does not need to reproduce everything in the original.

Check the hard parts

Validate external services, specialist technology, data access, and ongoing costs for your chosen scope.

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BUILD KIT DIFFICULTY
Starter

From the Build Kit assessment.

A reliable timeline needs an agreed scope and a technical check. Ask your agent to estimate the phases in BUILD_PLAN.md after that review.