Offline Flutter Expense Tracker App

I need a clean, simple personal expense tracker mobile app built with Flutter. The app must work fully offline: no login, no backend server, no cloud services and no paid APIs. All data stays on the user's phone.

REQUIRED FEATURES

1. Add / Edit / Delete Expenses
- Fields: amount, category, date, optional note
- Input validation (no empty or negative amounts)

2. Categories
- Default categories: Food, Transport, Shopping, Bills, Health, Entertainment, Other
- Users can add, rename and delete their own categories, each with a Material icon and a color

3. Monthly Budget
- User sets a monthly budget limit
- Progress bar showing spent vs. remaining
- Warning banner when spending passes 80% of the budget

4. Dashboard / Home Screen
- Total spent this month
- List of recent transactions
- Pie chart of spending by category (use fl_chart or a similar free package)

5. History and Filters
- View all expenses grouped by month
- Filter by category and date range
- Search by note text

6. Export
- Export expenses to a CSV file and share it with the device share sheet

7. Settings
- Light / Dark mode toggle
- Currency symbol selection
- "Clear all data" option with a confirmation dialog

TECHNICAL REQUIREMENTS

- Flutter (latest stable) and Dart
- Local storage: SQLite (sqflite) or Hive
- Use only free, open-source packages from pub.dev
- No Firebase, no API keys, no third-party accounts
- Use only Material icons and built-in Flutter widgets (no custom artwork required)
- Clean, well-organized code with a clear folder structure
- The app must build and run on an Android emulator without errors

DELIVERABLES

1. ZIP file containing:
- The complete Flutter project source code
- A built, installable Android APK (release or debug)
- A README with setup and build instructions

2. Demo video (screen recording from an emulator or device) showing every feature listed above working.

IMPORTANT: Please do NOT upload or host the code on GitHub or any other public repository. Final delivery must be the ZIP file plus the video only.

PAYMENT AND ACCEPTANCE

- Payment will be made only through Freelancer.com milestones.
- The milestone will be released only after I install the APK, test it, and confirm that all listed features work as described.
- If anything is missing or not working, you must fix it before payment is released.
- After payment, full ownership of the source code is transferred to me. The code must be original and must not be reused or resold.
- Free bug fixes for 7 days after delivery.

NOT INCLUDED (OUT OF SCOPE)

- Publishing to Google Play or the App Store
- iOS build (the code should stay Flutter cross-platform, but only the Android APK is required)
- User accounts, cloud sync or a backend

TIMELINE

3 to 5 days

HOW TO APPLY

Please briefly describe your Flutter experience and confirm you can deliver the ZIP file and demo video within 3 to 5 days. Bids that start with "Flutter Expense" will be reviewed first.