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.
App Overview
HeartWatch: Heart Rate Monitor
"HeartWatch is so good, you’d think Apple built the app itself." John Patrick Pullen, Time Magazine
$8.99 · In-app purchases
PRICE
$8.99
In-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
★ 4.7
13,635 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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Build Kit
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A product spec, screen plans, and build steps for your coding agent.
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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.
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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Free quick prompt For a smaller starting point
Quick prompt
Good fit for mobile-first iOS and Android prototypes with managed app scaffolding.
// RORK SYSTEM PROMPT
Rork plan preview for HeartWatch: Heart Rate Monitor: map the core Health & Fitness 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
Provide customizable date ranges for analytics.
Assumption to check: Limited historical data view
Validate with people who use this workflow before building.
Hypothesis 2
Implement advanced algorithms for better accuracy.
Assumption to check: Inaccurate heart rate readings in certain conditions
Validate with people who use this workflow before building.
Hypothesis 3
Add social features to share progress with friends.
Assumption to check: Limited social sharing features
Validate with people who use this workflow before building.
Hypothesis 4
Integrate with smartwatches and fitness bands.
Assumption to check: No integration with wearables
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
"HeartWatch is so good, you’d think Apple built the app itself." John Patrick Pullen, Time Magazine. Top 5 in Health & Fitness in 100+ countries. TOTAL PRIVACY HeartWatch has no user analytics tracking. No advertising plugins. No 3rd party code. No data upload. Ask your "free" heart app if they can say the same. ABOUT HEARTWATCH HeartWatch is the best way to get a complete picture of all the health & fitness information captured by your Apple Watch. NEWS - Explore the different News Editions to learn all about your health progress and trends. - Morning Briefing: read about your key health information to start your day - Fitness Habits: news all about your fitness trends with a dynamic fitness habit tracker WELLNESS - An intelligent view of all key heart rate metrics. Daytime, Sedentary, Sleeping, Waking & Workouts. - Detailed trend analysis including heart rate, blood pressure, HRV, blood glucose, blood oxygen (SpO2) and more. - Background heart rate alerts on Watch with context. - Note capture for individual heart rate readings. - Detailed ECG analysis ACTIVITY - Every day isn’t the same. Intelligent move, distance & steps goals based on your current habits. - Daily forecasting to help you stay on track to meet your goals. WORKOUTS - In depth analysis of heart rate, training summary, GPS maps and more. - A heart focussed workout app on the Watch with custom alerts to keep you in the right zone. - Detailed trend analysis. - Stream workout info from your Watch to your iPhone. JOURNAL & NOTES - Keep a daily journal with notes and measurements - View a detailed list with a complete overview of all notes, measurements and workouts - Input notes and measurements from your Watch or iPhone. Includes blood pressure, temperature, blood glucose, weight, waist circumference and body fat percent. GRAPHS & ANALYSIS - Over 30+ health metrics to view - Apply 7 day and 21 day trends to any metric, with the ability to overlap - View over 6 weeks up to 12 months EXPORT - Export for all health metrics & workouts. NOTHING IS MORE IMPORTANT THAN YOUR HEALTH Heart Watch is a very useful tool to get alerted about any possible health issues in a concise format that you can show your medical practitioner. INTEGRATION HeartWatch connects beautifully with the Eclipse Yourself and AutoSleep apps, our premier sleep, activity, recovery and readiness monitoring apps. HEART MONTH Featured app in the official Apple Heart Month 2022: https://www.apple.com/au/newsroom/2022/01/apple-celebrates-heart-month-with-new-resources-across-services REQUIREMENTS This app requires an iPhone that has the Health App installed. Heart readings are read from the Health Data Store which is ideally populated by your Apple Watch.
Written user reviews are not shown here. Check current App Store reviews >
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.
