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
Brush-Up
Brush up before you suit up! Whether you're a new umpire, a coach, or a parent learning the game, Brush Up is the fastest way to master Little League baseball rules.
$4.99 · In-app purchases
PRICE
$4.99
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.
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Combine features and design from your favorite apps.
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What should your app do differently? Your note travels with the kit so your coding agent builds around your idea.
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/
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.
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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 Brush-Up: map the core Sports 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
Offer personalized exercise plans based on user skill level and goals.
Assumption to check: Users often find sports training apps too generic and unpersonalized.
Validate with people who use this workflow before building.
Hypothesis 2
Implement detailed analytics and visual progress tracking with charts.
Assumption to check: Difficulty in tracking progress over time.
Validate with people who use this workflow before building.
Hypothesis 3
Provide a free trial or tiered pricing with clear benefit explanations.
Assumption to check: High subscription costs without clear value.
Validate with people who use this workflow before building.
Hypothesis 4
Introduce social sharing and community challenges to enhance user engagement.
Assumption to check: Limited social interaction and community features.
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
Brush up before you suit up! Whether you're a new umpire, a coach, or a parent learning the game, Brush Up is the fastest way to master Little League baseball rules. Learn with Flash Cards Quiz yourself on definitions, game scenarios, pitching rules, and baserunning with interactive flashcards. Each card links directly to the official rule so you can dig deeper. Track your progress across topics and jump into a Quick Session for 10 random cards when you're short on time. Chat with a Rules Expert Got a question? Just ask. Tap the mic and have a hands-free voice conversation with an AI rules expert grounded in the official Little League rulebook. Get concise, accurate answers with rule citations — perfect for quick clarification at the field or studying at home. Browse the Complete Rulebook Search and browse every rule organized by section — from definitions and equipment to pitching, baserunning, and umpire mechanics. Bookmark your favorites for quick reference. Why Brush Up? • 65+ flashcards across 4 topics with progress tracking • Voice-powered Q&A — ask any rule question naturally • Complete searchable rulebook with bookmarks • Conversation history so you can revisit past answers • Clean, simple design built for quick reference • All proceeds support local little league teams and players Perfect for umpires preparing for their first season, coaches brushing up before game day, and parents who want to understand what's happening on the field. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
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.
