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
Hammer Price
Hammer Price is the original way to follow all of your favorite collector car auctions at once, in real-time
Free · In-app purchases
PRICE
Free
In-app purchases
BUSINESS MODEL
Freemium
No overall Grossing estimate available
RATING
★ 3.3
42 ratings · Below Average
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/
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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 Hammer Price: map the core Business 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
Provide advanced filtering and sorting features.
Assumption to check: Limited auction visibility and filtering options
Validate with people who use this workflow before building.
Hypothesis 2
Implement a guided onboarding process.
Assumption to check: User interface can be confusing for new users
Validate with people who use this workflow before building.
Hypothesis 3
Design a more user-friendly subscription model.
Assumption to check: In-app purchase prompts can be intrusive
Validate with people who use this workflow before building.
Hypothesis 4
Optimize image loading and caching.
Assumption to check: Performance issues with heavy images
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
Hammer Price is the original way to follow all of your favorite collector car auctions at once, in real-time. Preview auction runlists, keep track of interesting lots, compare today’s prices with past results, and see what’s selling now. LIVE RESULTS Choose the sales you want to follow and add them to your Auctions list. Interested in seeing how a particular car does? Add it to your Favorites for quick reference. Opt for an alert and you’ll get notified before your car crosses the block or when it hammers. PORTFOLIO Put together a group of cars you want to track over time. Your Portfolio will chart matching results and email you an update when cars on your list sell at auction. YOUR WAY View results with or without commission, in seven currencies. CONTACT US Having a problem with the app? Let us know at [email protected]. Terms of Use: https://hammerpricelive.com/terms-of-use-app.html
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
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.
