App Overview

Greyline FT8 icon

Greyline FT8

JONATHAN MARK SCHULMAN · Utilities

Greyline FT8 is a highly portable, capable amateur radio app designed specifically for field operation with an iOS device

$3.99 · In-app purchases

PRICE
$3.99
In-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
4.8
12 ratings · Top 5%

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 included16 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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> SELECT BUILD PLATFORM:

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

// RORK SYSTEM PROMPT
Rork plan preview for Greyline FT8: map the core Utilities 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 advanced calculations and analysis tools.

Assumption to check: Limited features for advanced users

Validate with people who use this workflow before building.

Hypothesis 2

Simplify onboarding with guided tutorials.

Assumption to check: Complex onboarding process

Validate with people who use this workflow before building.

Hypothesis 3

Allow users to input and analyze multiple frequencies simultaneously.

Assumption to check: No support for multiple frequencies

Validate with people who use this workflow before building.

Hypothesis 4

Implement iCloud sync for user data and history.

Assumption to check: Lack of cloud backup

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

Greyline FT8 is a highly portable, capable amateur radio app designed specifically for field operation with an iOS device. I designed this app because I got very used to my full-stack FT8 solution: GridTracker, WSJT-X, PSK Reporter, WRL Desktop, several browser tabs, and more. But I didn't want the bulk and weight of a full Windows PC in the field. At the same time, while there are excellent and lightweight FT8 iOS solutions out there, they were lacking features I really wanted. Greyline is everything you need and nothing you don't. It automatically locates your grid square, performs callsign and calling station DXCC lookups (internet access required), and can even show you real-time spot data from PSK Reporter. Want to adjust your directional antenna? Now you've got the info you need to do it! Greyline also incorporates automated calling features. Gatherer mode calls CQ, responds to the first reply it gets, finishes the QSO and returns to calling CQ all without your input. On the other side of things, Hunter mode listens for CQ calls and pounces on them, finishing a QSO then returning to the live band to find the next. Or, take control of the conversation yourself with standard mode. That's the experience you're already used to from WSJT-X and other digital mode apps. Some other noteworthy features are: - Intelligent automatic free frequency selection - Dynamically adjusted audio delay for virtually drift-free message timing - PSK Reporter integrated Live Spots - Direct-to-QRZ, WRL and private Cloudlog logging and ADI export - Configurable waterfall settings - CQ addendums - CQ filtering for contesting and general courteous operation - Configurable retransmissions - Intelligent log recovery (didn't get that last 73 but want to log the contact anyway? Now you can!) - Log import and export - Antenna tuning - POTA Autospotting - One touch POTA activation and POTA.app-compatible ADIF export - Multiple POTA activation support - And so much more! Greyline uses audio VOX and not serial PTT. Most radios support this with simple cabling or an audio interface like a Digirig. For helpful tips on cabling and configuring popular radios, visit the Support URL below. Built by a ham, for hams, I'm very open to your feedback and hope Greyline can be your field companion. Want to share your own Field Notes (https://greylineft8.com/fieldnotes.html)? Email me at [email protected]!

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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
Advanced

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.