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.
practice and perform jazz standards on another level with quartet.
$16.99 · In-app purchases
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.
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.
A product spec, phased build plan, differentiation notes, and screen references.
Illustrative example: an invoice app for independent contractors. Your kit is tailored to the app you choose; this is not its generated content.
Goal: Send a clear invoice after finishing a job.
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.
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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Good fit for mobile-first iOS and Android prototypes with managed app scaffolding.
Rork plan preview for Quartet 4: map the core Music workflow, choose the smallest differentiated feature set, define the data and monetization boundaries, then prototype the riskiest user journey first.
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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
Assumption to check: Limited offline playback options
Validate with people who use this workflow before building.
Hypothesis 2
Assumption to check: In-app purchase confusion
Validate with people who use this workflow before building.
Hypothesis 3
Assumption to check: Limited social sharing features
Validate with people who use this workflow before building.
Hypothesis 4
Assumption to check: Basic search functionality
Validate with people who use this workflow before building.
Original App Store material. Ratings and screenshots describe the existing app, not proof of demand for your version.
practice and perform jazz standards on another level with quartet. volume 4 includes another 100 stunning jazz standards recorded exclusively by 6 of the world’s best jazz musicians. all ‘live’ studio recordings with intros and endings. whether you play jazz piano, guitar, saxophone, trumpet, bass, drums…simply mute your instrument from the quartet for the ultimate jazz play along. and for jazz singers too, each edition of quartet is an unrivalled collection of jazz backing tracks powerful enough to gig with. change key on the fly. speed up or slow down the audio seamlessly using the very latest audio technology. loop sections and slow them right down for practice. improve your skills with full screen animated chord diagrams for piano, guitar and ukulele. with the new search+ feature, you can build multi-app playlists using any of the songs from any of the 5 editions of quartet that you own. playlists are automated and auto-sync across each of your quartet apps. and once you’ve got songs just the way you want them, export the stereo mixes in seconds (free) or export the multitrack to remix or develop the separate parts in whatever daw you use (each multitrack is delivered to you as a garageband project via a low cost in app purchase). either way, all 100 recordings are offered to you royalty-free giving you endless creative possibilities. the 100 jazz standards in quartet volume 4 include improvisations in the style of… ‘affirmation’, ‘água de beber’, ‘alexander’s ragtime band’, ‘blue in green’, ‘born to be blue’, ‘cinema paradiso’, ‘chicken’, ‘ev’ry time we say goodbye’, ‘feel like makin’ love’, ‘got a match?’, ‘here there and everywhere’, ‘i get a kick out of you’, ‘it ain’t necessarily so’, ‘la fiesta’, ‘manhattan’, ‘nothing personal’, ‘poinciana’, ‘save your love for me’, ‘social call’, ‘surrey with the fringe on top’… and 80 more. you can install quartet on your ios devices plus your mac (‘apple silicon’ m series chips) at no extra cost. quartet volume 4. take your jazz standards play along to another level! hear more at www.quartetapp.com featured artists on quartet volume 4 guitar nigel price nigel has recorded with many big-name artists, performing on over 50 albums, most recently van morrison’s studio album ‘keep me singing’.currently, nigel is recording and touring with the nigel price organ trio. a former member of the james taylor quartet, nigel was voted the uk’s ‘best guitarist’ in the 2016 british jazz awards and is “…probably the most dynamic and gifted guitarist on the british jazz scene today” [all about jazz]. trumpet steve fishwick steve has performed and recorded with many leading european jazz musicians including sir john dankworth, george mraz, dado moroni, claus raibler, tony lakatos and the wdr big band. in the usa, steve has performed and recorded with anita o' day, ron carter, jimmy heath, peter erskine, eric harland, scott hamilton, herb geller, lanny morgan... saxophones and flutes andy panayi recording and performing credits include shirley bassey, jessye norman, paul mccartney, seth macfarlane, elaine paige, elvis costello, georgie fame, irene reed, elaine delmar, helen shapiro, madeline bell, patty austin, freddie hubbard, wynton marsalis, joe lovano, billy cobham… piano graham harvey recording and performing credits include incognito (md), stacey kent, george benson, m people, the jones girls, philip bailey, chaka khan, the bbc big band, madeline bell, jocelyn brown, mica paris, sir cliff richard… bass geoff gascoyne recording, performing and production credits include jamie cullum (md), sting, van morrison, bill bruford, mari wilson, paloma faith, georgie fame, gloria estefan, guy barker, charlie watts, chris standring, everything but the girl, benny golson, jacqui dankworth, john martyn, eartha kitt… drums sebastiaan de krom recording and performing credits include herbie hancock, john scofield, phil woods, jamie cullum, guy barker, wynton marsalis...
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Plan a focused first version with your coding agent. These are planning assumptions, not a delivery guarantee.
Choose one audience and one core workflow. Use the kit to agree on its screens, data, and acceptance criteria before building.
Decide which secondary features, integrations, and platform support can wait. Your version does not need to reproduce everything in the original.
Validate external services, specialist technology, data access, and ongoing costs for your chosen scope.
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.