Habit Tracker

A minimalist mobile habit tracker built with Expo (React Native + TypeScript). Track daily habits, view streaks, and visualize progress with a calendar heatmap — all stored locally on-device.

Features

• Add and complete daily habits with a single tap
• Automatic midnight reset — each day starts fresh
• Stats screen with streaks, completion percentages, and best day of week
• Calendar heatmap for visualizing consistency over time
• Dark theme throughout
• Local-first — all data stored on-device with SQLite

Tech Stack

• Expo SDK 54 (managed workflow)
• expo-router — file-based navigation
• expo-sqlite — local persistence (direct SQL, no ORM)
• React Context + useReducer — state management
• react-native-svg — custom calendar heatmap
• TypeScript

Getting Started

Prerequisites

• Node.js (LTS)
• Expo CLI
• iOS Simulator (macOS) or Android Emulator

Install & Run

npm install
npx expo start

Press i for iOS simulator or a for Android emulator.

Project Structure

app/              # expo-router screens (_layout, index, stats)
src/db/           # database singleton + SQL queries
src/context/      # HabitContext (global state + DB sync)
src/components/   # UI components (HabitItem, AddHabitInput, CalendarHeatmap, etc.)
src/hooks/        # useStats hook
src/constants/    # colors.ts, typography.ts (dark theme)

License

MIT