Compound259

A compound interest calculator for iOS. Enter a starting amount, monthly contribution, rate, and time horizon, and see what your money grows into. Everything runs on the device. No accounts, no ads, no tracking.

Download on the App Store

Screenshots

Calculator (dark)	Calculator (light)	Saved records	Learn

Features

• Future value with regular contributions and annual, semi-annual, quarterly, or monthly compounding
• Growth chart that shows how the balance builds over the years
• Breakdown of principal, contributions, and interest earned
• Quick inputs with steppers and preset amounts, so there is no typing
• Save scenarios, compare them later, and share them as images
• Learn tab that explains compound interest in plain terms
• Dark and light themes

Tech Stack

• Expo SDK 54 with React Native and TypeScript
• Expo Router for navigation
• AsyncStorage for on-device persistence
• react-native-svg for the chart

Getting Started

npm install
npx expo start

Then press i for the iOS simulator, a for the Android emulator, or scan the QR code with a development build on a device.

Release Build

Builds and App Store submission run through EAS:

npx eas build --platform ios --profile production --auto-submit

The production profile auto-increments the build number and submits to TestFlight.

Project Structure

app/
  (tabs)/
    index.tsx     # Calculator screen
    explore.tsx   # Saved records screen
    learn.tsx     # Learn tab
  _layout.tsx     # Root layout
components/ui/    # Reusable UI components
constants/        # Design tokens and themes
hooks/            # Custom hooks
utils/            # Finance math and formatting
docs/screenshots/ # README images

License

Private