App Overview

24-Hour Time Calculator icon

24-Hour Time Calculator

Richard Montoya · Productivity

24-Hour Time Calculator makes adding, subtracting, and scoring 24-hour (military) time fast and effortless.

$2.99 · In-app purchases

PRICE
$2.99
In-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
5.0
2 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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A product spec, screen plans, and build steps for your coding agent.

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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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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 24-Hour Time Calculator: map the core Productivity 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

Add features like reminders and timers.

Assumption to check: Limited functionality compared to comprehensive time management apps

Validate with people who use this workflow before building.

Hypothesis 2

Include 12-hour and AM/PM conversion features.

Assumption to check: Only supports 24-hour time conversion

Validate with people who use this workflow before building.

Hypothesis 3

Implement a history feature to log conversions.

Assumption to check: No history tracking of past conversions

Validate with people who use this workflow before building.

Hypothesis 4

Provide settings for theme adjustments and notifications.

Assumption to check: No user customization options

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

24-Hour Time Calculator makes adding, subtracting, and scoring 24-hour (military) time fast and effortless. Whether you're a pilot, dispatcher, shift worker, or anyone managing schedules and logs, this app is designed for you. Enter start and end times, calculate time differences, or quickly solve 24-hour time math for any need. Key Features: • Instantly add or subtract 24-hour (military) time • Quickly calculate time differences for shifts, schedules, or logs • Persistent Time: Easily save and reuse a constant value - no more retyping the same number again and again • Automatic Clock Wrapping: Results always stay within 24-hour format - no more confusing answers like "25:00" • Simple, modern interface - no clutter, no ads • Designed for aviation, logistics, transportation, shift work, and anyone who needs accurate time math • Works great with typical flight plan and scheduling formats ----- How It Works: 1. Enter your starting time. (Example: "13:15" for 1:15 PM.) 2. Add or subtract the desired value. (Example: add "2:50" to get "16:05".) 3. Use the persistent time feature to save a commonly used number (like an offset or fixed block time), so you never have to re-enter it. 4. All results are automatically wrapped to the 24-hour clock - no more odd answers like "25:00". ----- Stop struggling with mental math or spreadsheets - 24-Hour Time Calculator helps you get the job done with confidence, every time.

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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
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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.