This Odoo Flutter Backend is a simple example of a book store back-end with Odoo for a flutter app with an API controller.
http://localhost:8080/api/books{
   "success":true,
   "data":[
      {
         "name":"Book name",
         "description":"dfsdf",
         "state":"draft",
         "publish_date":"2020-05-18",
         "language":"en",
         "isbn":"23234324",
         "price":20.0,
         "author":"Ahmed",
         "publisher":"Dar",
         "categories":[
            "Arabic / \u0627\u0644\u0652\u0639\u064e\u0631\u064e\u0628\u064a\u0651\u0629"
         ]
      }
   ]
}