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
WhatsApp Messenger
Bring your group together on WhatsApp.
Free · In-app purchases
OVERALL US RANK
#21
Free · all categories
REVENUE (Est)
$451K/mo
$265K - $637K
RATING
★ 4.7
18,897,914 ratings · Top 15%
Evidence scope: #21 is the current overall US Free chart position. 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 included18 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 WhatsApp Messenger: map the core Social Networking 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
App evidence
Original App Store material. Ratings and screenshots describe the existing app, not proof of demand for your version.
Screenshots
< Scroll to see more >
App Store description
Bring your group together on WhatsApp. WhatsApp from Meta is a free messaging and calling app for the people and groups in your life. Bring your best friends, parent group, study group, or neighborhood together to chat, make plans, and share moments. Get everyone into the conversation Invite people with a link or QR code. Names and profile photos help you know who's who, and shared message history helps new members catch up. Make plans together Create events and track RSVPs. Use polls to choose a date or make a decision. Share your live location to find each other, and send documents up to 2GB. Keep your group organized Pin important messages. Admins can approve requests to join, and set group permissions. Have several related groups? Bring their chats and announcements together in a Community. Share more than messages Send HD photos and videos, voice messages, and short video notes. Make conversations your own with custom stickers, reactions, GIFs, and chat colors and backgrounds. Share everyday moments through Status-updates that disappear after 24 hours. Get together on a call Make unlimited voice and video calls with up to 32 people, with screen sharing, effects, and reactions. Speak freely Your personal messages and calls—including group chats and calls—stay private with end-to-end encryption. Not even WhatsApp can read or listen to them. Turn on disappearing messages to choose when your messages disappear. WhatsApp works on your phone, computer, tablet, and supported watch, including on slower connections. --------------------------------------------------------------------------- If you have any feedback or questions, please go to WhatsApp > Settings > Help > Contact Us Terms of Service: https://www.whatsapp.com/legal/terms-of-service Learn more about messaging privately: https://www.whatsapp.com/privacy Learn more about WhatsApp safety: https://www.whatsapp.com/security
Written user reviews are not shown here. Check current App Store reviews >
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 enhanced privacy settings, including end-to-end encryption and disappearing messages.
Assumption to check: Limited privacy features for users
Validate with people who use this workflow before building.
Hypothesis 2
Create better group management features, such as admin roles and permissions.
Assumption to check: Difficulty in managing group chats
Validate with people who use this workflow before building.
Hypothesis 3
Improve real-time notification system for message delivery and read receipts.
Assumption to check: Inconsistent message delivery notifications
Validate with people who use this workflow before building.
Hypothesis 4
Allow users to customize themes and chat backgrounds.
Assumption to check: Lack of customization options for UI
Validate with people who use this workflow before building.
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
Supabase
Zustand
React Navigation
BUILD KIT DIFFICULTY
Expert
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.
