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
Finance Calculators
finance calculator is an easy to use app that contains 96 financial calculators split into 5 categories:
$2.99 · In-app purchases
PRICE
$2.99
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 Finance Calculators: map the core Finance 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
Expand the range of calculators available.
Assumption to check: Limited calculator options compared to competitors
Validate with people who use this workflow before building.
Hypothesis 2
Allow users to customize calculator themes or layouts.
Assumption to check: Lack of user customization features
Validate with people who use this workflow before building.
Hypothesis 3
Implement a history feature to track previous calculations.
Assumption to check: No saved history or previous calculations
Validate with people who use this workflow before building.
Hypothesis 4
Add features for users to analyze their financial data.
Assumption to check: No in-depth financial insights or analytics
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
finance calculator is an easy to use app that contains 96 financial calculators split into 5 categories: general finance includes 30 calculators: - annuity - future value - annuity - future value w/ continuous compounding - annuity - (fv) solve for n - annuity - payment (pv) - annuity - payment (fv) - annuity - (pv) solve for n - annuity - present value - avg collection period - annuity - pv factor - annuity due - present value - annuity due - future value - annuity due payment (pv) - annuity due payment (fv) - doubling time - doubling time - cont. compounding - doubling time - simple interest - future value - fv - continuous compounding - future value factor - growing annuity - future value - growing annuity - payment (pv) - growing annuity - payment (fv) - growing annuity - present value - growing perpetuity - present value - number of periods - pv & fv - perpetuity - present value - pv - continuous compounding - present value factor - rule of 72 banking includes 11 calculators: - annual percentage yield - balloon loan - payments - compound interest - continuous compounding - debt to income ratio (d/i) - loan - balloon balance - loan - payment - loan - remaining balance - loan to deposit ratio - loan to value (ltv) - simple interest stocks/bonds includes 28 calculators: - bid ask spread - bond equivalent yield - book value per share - capital asset pricing model - capital gains yield - current yield - diluted earnings per share - dividend payout ratio - dividend yield - stock - dividends per share - earnings per share - equity multiplier - estimated earnings - geometric mean return - holding period return - net asset value - preferred stock - price to book value - price to earnings (p/e ratio) - price to sales (p/s ratio) - risk premium - stock - pv with constant growth - stock - pv with zero growth - tax equivalent yield - total stock return - yield to maturity - zero coupon bond value - zero coupon bond yield corporate finance includes 25 calculators: - asset to sales ratio - asset turnover ratio - avg collection period - contribution margin - current ratio - days in inventory - debt coverage ratio - debt ratio - debt to equity ratio - discounted payback period - equivalent annual annuity - free cash flow to equity (fcfe) - free cash flow to firm (fcff) - interest coverage ratio - inventory turnover ratio - net present value - net profit margin - net working capital - payback period - quick ratio - receivables turnover ratio - retention ratio - return on assets (roa) - return on equity (roe) - return on investment financial markets includes 2 calculators: - rate of inflation - real rate of return finance calculator also includes: - formula for each calculator - description for each calculator - copy button - clear button
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 Native
Expo
react-navigation
react-native-paper
formik
expo-sqlite
BUILD KIT DIFFICULTY
Intermediate
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.
