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.
EMPOWER YOUR BUSINESS - Throw away your old calculators
$9.99 · 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.
Kit ready. Verify your email to download it.
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.
JavaScript is required to complete mailbox verification.
Good fit for mobile-first iOS and Android prototypes with managed app scaffolding.
Rork plan preview for Go Calc: map the core Business workflow, choose the smallest differentiated feature set, define the data and monetization boundaries, then prototype the riskiest user journey first.
Preview ready. Verify your email to reveal and copy the full prompt.
JavaScript is required to complete mailbox verification. Return to this prompt preview.
Affiliate link: CloneChart may earn a commission at no extra cost
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 historical data visibility
Validate with people who use this workflow before building.
Hypothesis 2
Assumption to check: No customization options for calculator layout
Validate with people who use this workflow before building.
Hypothesis 3
Assumption to check: Poor user onboarding experience
Validate with people who use this workflow before building.
Hypothesis 4
Assumption to check: Lack of advanced functions like graphs
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.
EMPOWER YOUR BUSINESS - Throw away your old calculators. Transform everyday calculations. Create calculators for your business right on your iPhone or iPad. Create your own calculator apps right on your iPhone or iPad. In minutes your business specific calculations become a breeze. Create a calculator for each type of problem you need to solve using formula similar to those found in spreadsheets. Go Calc has been helping businesses like yours get the right answers since 2008: "It turned into a mission-critical app when I created a set of formulas for all my estimating and billing." "I own a Retail store and have to work out margins every day." "I use this app nearly every day for scuba gas blending. It saves a huge amount of time." "I have several elaborate pricing formulas that I use at work. ... I can quickly adjust two simple numbers, my price and my markup ... and give me a suggested price." "I created several functions that make it easier to interpret logistic regression results, and it works like a charm!" "I work in the Road Construction industry and have not found anything close to this app." "This app has made my job so much easier and almost fun." Examples of calculators you could create: * Quickly work out potential profit when negotiating with a customer * Estimate costs using a set of business specific variables * Determine how much of a consumable you need Go Calc allows you to quickly create new calculations by setting up variables and formulas on your iPhone or iPad. Creating a new calculator is easy: 1. Tap to add a new calculator 2. Give it a name 3. Add some variables (the inputs to the calculations) 4. Create one or more formulas to get your results 5. Go Calc! Each calculator you create can be reused again and again. Calculators can be easily found by filing them into categories. Formulas in Go Calc share much with the formulas you write in your favorite spreadsheet. Over 50 functions can be used including IF, MAX, SIN, LOG, IPMT, RANDBETWEEN. Import and export your calculations. Backup all your calculations easily and without the need to install any software on your PC or Mac. Create calculators and then share them with other Go Calc users in your business.
Written user reviews are not shown here. Check current App Store reviews >
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.