Habit Tracker App

Build a habit tracking application with:

## Habits
- Create habit: name, icon, frequency (daily/weekly/custom days), target time
- Color-coded habit cards on the main screen
- One-tap to mark habit complete for today
- Streak counter (current streak, best streak)
- Habit categories: Health, Productivity, Learning, Fitness, Mindfulness

## Calendar View
- Monthly view showing completion grid (like GitHub contribution graph)
- Color intensity based on completion percentage
- Click a date to see that day's habit status
- Week view as alternative

## Statistics
- Overall completion rate (this week, this month, all time)
- Per-habit analytics: completion rate trend chart
- Best day of the week for consistency
- Streak records and milestones
- Weekly/monthly progress comparison

## Reminders
- Push notification reminders per habit
- Custom time for each reminder
- Morning routine and evening routine grouping

## Gamification
- Points for completing habits
- Level system based on total points
- Achievement badges (7-day streak, 30-day streak, 100%, etc.)
- Weekly challenge: complete all habits every day this week

Design: Friendly, motivational UI with rounded corners, soft colors, and celebration animations when completing habits. Dark mode support.