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
Bluebikes
Bluebikes is metro-Boston’s public bike share system
Free · In-app purchases
PRICE
Free
In-app purchases
BUSINESS MODEL
Freemium
No overall Grossing estimate available
RATING
★ 4.4
2,159 ratings · Top 30%
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 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.
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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 Bluebikes: map the core Navigation 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 real-time bike availability updates and notifications.
Assumption to check: Limited bike availability during peak hours
Validate with people who use this workflow before building.
Hypothesis 2
Provide an onboarding tutorial to guide first-time users.
Assumption to check: Confusing navigation for new users
Validate with people who use this workflow before building.
Hypothesis 3
Optimize performance for older hardware.
Assumption to check: App crashes reported on older devices
Validate with people who use this workflow before building.
Hypothesis 4
Allow users to view nearby stations and previous rentals offline.
Assumption to check: Lack of offline functionality
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
Bluebikes is metro-Boston’s public bike share system. With thousands of bikes available 24/7 at hundreds of stations throughout Metro-Boston, Bluebikes is one of the most popular bike shares in the country. Use the app to find your closest station and purchase a pass. Then unlock one of Bluebikes' safe, sturdy, easy to ride bikes, and get riding right away. When you’re done riding, simply return the bike to an available dock at any station in the network. The app will show you all station locations, with real-time bike and dock availability, and you can save your favorites for later reference. Tap a station pin or location and the app will show you the best route to get there. Ideal for one-way trips, commutes to work or school, running errands, meeting friends for dinner, going to a game, or just cruising around metro-Boston to see the sights. All trips under 45 minutes are included for members (the app will track your time for you). Take as many rides as you want during the term of your pass. Enjoy the ride!
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.
SUGGESTED BUILD STACK
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BUILD KIT DIFFICULTY
Advanced
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.
