App Overview

Signal Call icon

Signal Call

Matt Johnson · Sports

Signal Call is a wireless pitch calling system that lets baseball and softball coaches send pitch signals directly to a catcher's Apple Watch.

$1.99 · In-app purchases

PRICE
$1.99
In-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
N/A
No ratings yet

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 included15 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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Good fit for mobile-first iOS and Android prototypes with managed app scaffolding.

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Rork plan preview for Signal Call: map the core Sports 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

Implement advanced filtering and sorting options for better user experience.

Assumption to check: Difficulty in finding relevant events due to poor filtering options

Validate with people who use this workflow before building.

Hypothesis 2

Add features for users to communicate, such as comments and direct messaging.

Assumption to check: Limited user engagement features, like comments or messaging

Validate with people who use this workflow before building.

Hypothesis 3

Implement an algorithm to suggest events based on user preferences.

Assumption to check: Lack of personalized recommendations for events

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

Signal Call is a wireless pitch calling system that lets baseball and softball coaches send pitch signals directly to a catcher's Apple Watch. No more complicated hand signals. No more runners stealing signs. Just tap your phone, and your catcher sees the pitch type and location instantly on their wrist. ---------------------------- HOW IT WORKS 1. Use your existing paired Apple Watch and iPhone 2. Select a pitch type (Fastball, Curveball, Changeup, etc.) 3. Tap a zone on the 3x3 strike zone grid 4. Your catcher sees the call instantly on their watch The watch displays pitch type, location, and a visual zone grid with color-coded pitch categories. A vibration alert ensures the catcher never misses a call. ---------------------------- PITCH CALLING FEATURES • 10 pitch types: Fastball, 2-Seam, Cutter, Sinker, Curveball, Slider, Changeup, Splitter, Knuckleball, Screwball • 13 location zones: 9-zone strike zone plus high, low, inside, and outside • Custom pitch codes and sign numbers • Resend last pitch with one tap • Works for both Baseball and Softball ---------------------------- DEFENSIVE PLAYS Send quick signals for pickoffs, pitchouts, and intentional walks. (PRO) Create unlimited custom plays with your own codes and names. ---------------------------- GAME MANAGEMENT (Pro) Track complete games from first pitch to final out: • Record opponent lineups with the lineup scanner - just take a picture of a lineup card and Signal Call extracts batter names and numbers automatically • Track pitch-by-pitch results: balls, strikes, fouls, and in-play outcomes • Record at-bat results: hits, outs, walks, strikeouts, and more • Monitor pitch counts and pitcher statistics in real-time • View current batter's previous at-bats from the same game • Automatic inning advancement when three outs are recorded • Pause and resume games across sessions ---------------------------- STATISTICS & HISTORY (Pro) • Pitcher stats: total pitches, innings pitched, strike percentage, first-pitch strike percentage • Game history with detailed pitch-by-pitch records • Filter stats by pitcher, opponent, or date range • Browse opponent batting history across multiple games ---------------------------- TEAM MANAGEMENT (Pro) • Build and save your pitcher roster • Save opponent team rosters for future matchups • Quick lineup creation from saved rosters • Undo recent actions if you make a mistake ---------------------------- DEVICE CONNECTIVITY • Real-time connection status between your iPhone and Apple Watch • Fast, low-latency signal delivery so calls arrive the instant you tap ---------------------------- REQUIREMENTS • iPhone running iOS 17.0 or later • Apple Watch Series 3 or later ---------------------------- SUBSCRIPTION Signal Call offers a free tier with full pitch calling and play signaling. Upgrade to Signal Call Pro for game management, statistics tracking, lineup scanning, and roster management. Signal Call Pro is an auto-renewable subscription, available as: • Signal Call Pro (Monthly) — $9.99 per month • Signal Call Pro (Yearly) — $59.99 per year Payment will be charged to your Apple ID account at confirmation of purchase. The subscription automatically renews unless it is canceled at least 24 hours before the end of the current period. Your account will be charged for renewal within 24 hours prior to the end of the current period. You can manage or cancel your subscription anytime in your App Store account settings after purchase. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://signalcall.app/privacy.html ---------------------------- Stop worrying about sign stealing. Start calling pitches with confidence.

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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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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.