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
Cooper Test
CooperTest es la forma más sencilla de hacer el Test de Cooper y conocer tu capacidad cardiovascular real.
$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.
Build your own version
Build Kit
Make this idea yours
A product spec, screen plans, and build steps for your coding agent.
First kit free with a verified email
Add to a Remix
Combine features and design from your favorite apps.
Kit ready. Verify your email to download it.
Generating… usually about a minute.
Make it yours Optional
What should your app do differently? Your note travels with the kit so your coding agent builds around your idea.
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/
Preview a sample Build Kit No email needed
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.
JavaScript is required to complete mailbox verification.
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 Cooper Test: 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.
Preview ready. Verify your email to reveal and copy the full prompt.
JavaScript is required to complete mailbox verification. Return to this prompt preview.
Continue in Rork >
Affiliate link: CloneChart may earn a commission at no extra cost
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 more fitness tests and challenges to keep users engaged.
Assumption to check: Limited test variety may lead to user boredom.
Validate with people who use this workflow before building.
Hypothesis 2
Add social sharing and leaderboard features to encourage competition.
Assumption to check: Lack of social features reduces motivation.
Validate with people who use this workflow before building.
Hypothesis 3
Provide users with personalized insights and improvement suggestions post-test.
Assumption to check: No personalized feedback after tests.
Validate with people who use this workflow before building.
Hypothesis 4
Implement reminder notifications to encourage regular testing.
Assumption to check: No reminders for testing schedule.
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
CooperTest es la forma más sencilla de hacer el Test de Cooper y conocer tu capacidad cardiovascular real. El Test de Cooper es una prueba científicamente validada que mide tu resistencia aeróbica: corres durante 12 minutos intentando recorrer la mayor distancia posible. A partir de esa distancia, la app calcula tu VO₂ Max y te clasifica en una de cinco categorías (Excelente, Bueno, Promedio, Malo o Muy Malo) ajustada a tu edad y sexo biológico, siguiendo las tablas oficiales del test. CÓMO FUNCIONA — Abre la app, configura tu edad y sexo en el perfil — Pulsa Empezar y corre durante 12 minutos — La app avisa a los 6 minutos ("mitad de tiempo") y en el último minuto ("último minuto, acelera") — Al acabar suena un pitido y la app muestra tu distancia, VO₂ Max y clasificación — El resultado se guarda automáticamente en la app Salud FUNCIONA CON APPLE WATCH Si tienes Apple Watch, la app se instala también en el reloj y añade la frecuencia cardíaca en tiempo real durante el test. Puedes hacer el test directamente desde el Watch, sin sacar el iPhone del bolsillo. FUNCIONA CON LA PANTALLA BLOQUEADA El GPS sigue midiendo incluso con el iPhone bloqueado o con la app en segundo plano. No necesitas llevar el teléfono en la mano. HISTORIAL EN LA APP SALUD Todos tus tests se guardan en la app Salud de Apple, incluyendo el VO₂ Max calculado. Desde el historial de CooperTest puedes consultar tus resultados anteriores o eliminar los que no quieras. PRIVACIDAD TOTAL CooperTest no tiene servidores propios, no recopila datos, no muestra publicidad y no comparte ninguna información con terceros. Todo queda en tu dispositivo y en la app Salud de Apple. SIMPLE Y SIN DISTRACCIONES Sin suscripciones, sin registro, sin publicidad. Una sola función, bien hecha.
Written user reviews are not shown here. Check current App Store reviews >
Screenshots
< Scroll to see more >
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.
SUGGESTED BUILD STACK
React Native
Expo
React Navigation
axios
react-native-chart-kit
shadcn/ui
BUILD KIT DIFFICULTY
Intermediate
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.
