Implement functionalities & backend to a flutter+firebase(firestore) android and ios app

We develop a flutter, firebase (firestore) app. the UI is ready and fuctional but the backend is to be developer (and therefore flutter code will need the required adjustments to facilitate the changes). There is a list of 76 functionalities in the document that follows and a NON NEGOTIATABLE max budget of 350€. You will have to deliver them with the current(1 to 76) order in batches of 25 (1-25,26-50,51-76). For the 1st you will receive 25%, for the 2nd 45% for the 3rd 30%. In case at least 1 item of each batch is not delivered there is no payment and you cannot proceed to the next batch. At the end of each week you will have to send me in order to be able to validate the weekly progress in full through my emulator: a) the entire code b)an export of the firestore database c)any new parameterazations & instructions required d) update per item within the batch In case a batch exceeds 1 month development the project is cancelled. The 2nd sheet of the document has the required db schema in SQL approach given though that firecloud is NoSQL we will need to adjust accordingly. This is the 2nd phase of the project out of 5 and in case your job is considered satisfactory you will be offered the next phase. For the specific job we will sign NDA and IP agreements. [login to view URL]