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.
Every calculation
$4.99 · 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.
First kit free with a verified email
Combine features and design from your favorite apps.
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Generating… usually about a minute.
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 CalcTape Paper Tape Calculator: map the core Finance workflow, choose the smallest differentiated feature set, define the data and monetization boundaries, then prototype the riskiest user journey first.
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Affiliate link: CloneChart may earn a commission at no extra cost
Original App Store material. Ratings and screenshots describe the existing app, not proof of demand for your version.
Every calculation. In context. CalcTape combines a calculator, an editable calculation tape and space for notes. Plan a trip, check shopping costs, or track expenses while keeping your numbers and notes together. KEEP EVERY STEP IN VIEW Enter several items, create subtotals and add comments beside the numbers. Use arithmetic, percentages, powers and other functions while keeping longer calculations easy to follow. CHANGE A FIGURE, UPDATE THE RESULTS Edit a number or an operator, insert a line or remove an item. CalcTape recalculates the results below automatically. Undo and Redo let you reverse and restore changes. SAVE YOUR WORK Keep calculations as documents, reopen them later and reuse them as templates. The document list shows the storage location, date and line count. Choose whether a document opens at the beginning, at the last position or at the end. MAKE IT YOUR OWN Customize keyboard layouts and create user keys for frequently used functions or text. Choose from five themes, including Dark Night with a dark calculation tape, keyboard and dialogs. SHARE AND CONTINUE Share calculations as text, HTML or CalcTape files through the iOS share sheet, or print them. Use iCloud Drive to access your documents on other devices. FOR IPHONE AND IPAD The calculation tape and keyboard adapt to the app window. On iPad, work alongside another app. CalcTape is now also available in Ukrainian and Malay. Manual: https://help.calctape.com/ios Support: [email protected]
Written user reviews are not shown here. Check current App Store reviews >
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 functionality for advanced calculations
Validate with people who use this workflow before building.
Hypothesis 2
Assumption to check: Lack of visual themes or customization options
Validate with people who use this workflow before building.
Hypothesis 3
Assumption to check: No export functionality beyond PDF
Validate with people who use this workflow before building.
Hypothesis 4
Assumption to check: Limited accessibility features
Validate with people who use this workflow before building.
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.