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
Number Riddle: Crack the Code
“Number Riddle” is a simple yet highly challenging number deduction game.
$0.99 · In-app purchases
PRICE
$0.99
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 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.
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 Number Riddle: Crack the Code: map the core Entertainment 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
Introduce user-generated riddles or daily challenges to keep content fresh.
Assumption to check: Limited variety of riddles can quickly lead to user boredom.
Validate with people who use this workflow before building.
Hypothesis 2
Add social sharing features and leaderboards to encourage competition.
Assumption to check: Lack of social features may reduce engagement.
Validate with people who use this workflow before building.
Hypothesis 3
Clarify benefits of premium content and offer tiered pricing for better user understanding.
Assumption to check: In-app purchase structure might be unclear to users.
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
“Number Riddle” is a simple yet highly challenging number deduction game. Using limited clues, you must uncover a hidden 3-digit code. Each guess provides precise feedback: whether the numbers are correct and whether their positions are correct. Step by step, you’ll use logic to get closer to the answer. It may seem simple, but it’s truly brain-burning. 【Features】 • Classic logic-based gameplay • Each round takes only a few minutes — perfect for quick play anytime, anywhere • Clear feedback system: correct position / correct number / completely wrong • Multiple difficulty levels, from beginner to advanced 【Game Modes】 • Level Mode: Unlimited stages to continuously challenge your reasoning skills • Daily Challenge: One puzzle every day — compete with players around the world 【Why It’s Addictive】 • That constant feeling of being “just one step away” from the answer • Simple rules combined with deep strategy • Perfect for short breaks — the more you play, the more hooked you get Can you crack the code in the fewest moves? Download now and start your logic challenge.
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
Starter
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.
