App Overview

COLREG 72: safety at sea icon

COLREG 72: safety at sea

Smirnov Yury · Education

COLREG 72 is a complete study and reference app for the International Regulations for Preventing Collisions at Sea (COLREGs)

$3.99 · In-app purchases

PRICE
$3.99
In-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
4.8
116 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 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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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 COLREG 72: safety at sea: map the core Education 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

Incorporate gamification features like quizzes and badges.

Assumption to check: Limited interactive elements for engaging learning.

Validate with people who use this workflow before building.

Hypothesis 2

Add offline downloads for rules and quizzes.

Assumption to check: No offline access to content.

Validate with people who use this workflow before building.

Hypothesis 3

Enhance UI/UX with a cleaner design and better organization.

Assumption to check: User interface can feel cluttered.

Validate with people who use this workflow before building.

Hypothesis 4

Implement social sharing for achievements and progress.

Assumption to check: Lack of social features for sharing progress.

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

COLREG 72 is a complete study and reference app for the International Regulations for Preventing Collisions at Sea (COLREGs). Built for maritime students, merchant navy officers, yacht captains, and anyone preparing for a maritime exam. WHAT IS INCLUDED - Full text of all 72 COLREG rules (Annexes I through IV) - Theory study with illustrations - Navigation lights identification quizzes - Rule-based tests with answer explanations - Exam mode — a timed mock exam across all the rules with a final score and a full mistake review - Cross-references between rules and theory — open in popup overlays so you never lose your place HOW IT WORKS Theory and rules are linked throughout the app. When you answer a quiz question incorrectly or open a hint, a direct link appears to the exact theory section that covers the topic. Review the rule, then return to the quiz. The app tracks which theory sections you have read, so you always know where you left off and what still needs attention. EXAM MODE Simulate the real test. The exam is timed and draws questions from across all the rules. When time runs out, you get a clean result screen with your score and every mistake listed. Tap a wrong answer to see the explanation, the original comment from the question card, and a direct link to the relevant rule — so every attempt teaches you something. READING Reading is fully customizable: choose from multiple font types, adjust the font size, and switch between three color themes — light, sepia, and dark — for comfortable study in any lighting condition. Layouts are tuned for both iPhone and iPad. WHO IT IS FOR - Maritime students at nautical colleges and academies - Merchant navy officers preparing for OOW, Chief Mate, or Master exams - Yacht skippers and RYA / ASA candidates - Coastal and offshore sailors who need a reliable collision avoidance reference - Anyone sitting a maritime authority exam (MCA, USCG, AMSA, Transport Canada, MNI) WHY COLREG 72 International collision avoidance rules are the foundation of safe navigation. Whether you are studying for the first time or refreshing knowledge before an exam, this app gives you the full text, visual aids, practice tests, and a realistic exam mode to build true confidence. One-time purchase. No subscription. No ads. Study offline, anytime. Download COLREG 72 and arrive at your exam prepared.

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Build scope

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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.

SUGGESTED BUILD STACK
React Native
Expo
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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.