Hello, there
I have gone throough your job description and understood your project scope.
You are need the food delivery application in the cross platform in flutter.
I am working on the flutter/ dart, react native, ionic, cross platform and works on the API's and also third party API's integration.
Let's initiate the chat so that we can discuss in detail, there I will be show you the same of the food application delivery application. I have the some samples of the food delivery app and give you more idea about your project technology, which is best to integrate in the code and many other free services are also provides.
Thanks & Regards
Vikas Gupta