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
Decimal (.)
The iOS Decimal App was created in response to requests by visitors to our popular https://decimal.info web application
$0.99 · In-app purchases
PRICE
$0.99
In-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
N/A
No ratings yet
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.
Build your own version
Build Kit
Make this idea yours
A product spec, screen plans, and build steps for your coding agent.
First kit free with a verified email
Add to a Remix
Combine features and design from your favorite apps.
Kit ready. Verify your email to download it.
Generating… usually about a minute.
Make it yours Optional
What should your app do differently? Your note travels with the kit so your coding agent builds around your idea.
What's included15 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.
JavaScript is required to complete mailbox verification.
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 Decimal (.): map the core Utilities 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.
Continue in Rork >
Affiliate link: CloneChart may earn a commission at no extra cost
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
Add support for complex operations like fractions and percentages.
Assumption to check: Limited functionality for advanced calculations
Validate with people who use this workflow before building.
Hypothesis 2
Implement features to share results via clipboard or social media.
Assumption to check: No way to export or share calculations
Validate with people who use this workflow before building.
Hypothesis 3
Enhance UI with themes and customization options for users.
Assumption to check: Lack of visual design options
Validate with people who use this workflow before building.
Hypothesis 4
Introduce a feedback section for users to report issues or suggest features.
Assumption to check: No user feedback mechanism
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
The iOS Decimal App was created in response to requests by visitors to our popular https://decimal.info web application. Our visitors wanted a standalone tool that could be used to determine decimal place values, in addition to providing access to many of our decimal calculators and converters. The Decimal app has a lot to offer! We took all of the knowledge from our website to create useful tools, calculators, and converters related to decimals. This app can show you decimal place names and values. It can also round decimal numbers to one or two decimal places. Furthermore, the Decimal App can solve common decimal-related math problems. For example, it can turn a decimal number into a percent or a fraction. This app can also convert decimals into other number systems, like hexadecimal and binary. The app does not have subscription fees, In-App purchases, tracking, or ads. You just get full and complete access to all 10+ decimal tools, decimal calculators, and decimal converters. The app does not require an Internet connection, so you can use it anytime and anywhere. The app is intuitive, clutter-free, fast to operate, and easy to use. We hope that the Decimal App will become one of your favorite math apps.
Written user reviews are not shown here. Check current App Store reviews >
Screenshots
< Scroll to see more >
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
React Navigation
Zustand
Expo
React Native Reanimated
Expo-LinearGradient
BUILD KIT DIFFICULTY
Starter
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.
