Day 1-2: Set up Flutter environment, create a new Flutter project.
Day 3-4: Design the app's home screen, including product categories and featured items.
Day 5-7: Implement navigation to product details pages, design and implement cart functionality.
Day 8-10: Create user authentication and registration screens.
Day 11-13: Develop user profile management and order history features.
Day 14-16: Integrate payment gateway or simulate payment process.
Day 17-18: Implement search functionality, refine UI design, and user experience.
Day 19-20: Test extensively, fix any remaining bugs, and ensure smooth app navigation and performance.