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
Prosa
Prosa is a free audiobook app with 24 classic works of literature, ready to listen the moment you download
$2.99 · In-app purchases
PRICE
$2.99
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.
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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 Prosa: map the core Books 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
Implement personalized recommendations based on user reading history.
Assumption to check: Difficulty in discovering new books
Validate with people who use this workflow before building.
Hypothesis 2
Add discussion boards or groups for users.
Assumption to check: Limited community interaction features
Validate with people who use this workflow before building.
Hypothesis 3
Implement reliable cloud syncing with backend.
Assumption to check: Inconsistent data syncing across devices
Validate with people who use this workflow before building.
Hypothesis 4
Integrate social media sharing for reading achievements.
Assumption to check: Lack of social sharing 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
Prosa is a free audiobook app with 24 classic works of literature, ready to listen the moment you download. No account required, no ads, no subscriptions — just great books. Every title comes from a public-domain library, narrated and split into chapters so you can pick up right where you left off. The full collection includes 781 chapters of the world's most celebrated writing. THE LIBRARY - Beowulf - Alice's Adventures in Wonderland - A Christmas Carol - Great Expectations - Oliver Twist - The Adventures of Sherlock Holmes - The Hound of the Baskervilles - The Great Gatsby - Grimm's Fairy Tales - The Iliad - The Odyssey - The Call of the Wild - White Fang - The Prince - Moby-Dick - Frankenstein - The Strange Case of Dr Jekyll and Mr Hyde - Treasure Island - Dracula - Adventures of Huckleberry Finn - The Adventures of Tom Sawyer - Twenty Thousand Leagues Under the Sea - The Time Machine - The War of the Worlds FEATURES - Listen on iPhone or Apple Watch - Transfer chapters to your watch for phone-free listening - Track your progress across every book and chapter - Adjustable playback speed - Auto-advance to the next chapter - Sleep timer - Complications for your watch face showing current book and progress - Syncs listening progress between iPhone and Apple Watch DESIGNED FOR APPLE WATCH Prosa is built as a full watch experience. Browse the library, download chapters from your iPhone, and listen directly from your wrist — perfect for walks, runs, or falling asleep without your phone nearby. ALL FREE, FOREVER There are no in-app purchases, no premium tiers, and no tracking. Just open the app and start listening.
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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.
SUGGESTED BUILD STACK
React Native
Expo
Supabase
Zustand
React Navigation
React Native Reanimated
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.
