build me a flutter app (provide cost and timeline upfront)

- flutter app
- Home
- About
- text
- Contact
- form and text
- Order now
- order form
- payment method
- credit card
- cash on delivery
- sign in/up
- sign up
- form take username and password from the user
- Sign in
- login form
- user home page
-ongoing order
- order detail
- order status (tracking) details will be provided
- previous orders
- previous orders details
- account info
- edit username or password
- employee home page
- orders
- update order status

- the app support English and Arabic languages.
- the app support SQL DB.
- we provide colors and font and ERD.
- main page(view) contains a header and footer.
- employee accounts are created by admin only.
- open the attached document for a better view.