Build an App - Preferably on Flutter

We require an Android app developer (plus if you also have iOS experience) to complete the development of an app, we currently have the back covered (it is 90% and the administration panel in a 60% web app ), the app must allow: • An authentication process on behalf of Google using mobile services. • A registration view with address validation using the Google Maps function. A validation of the data must be included, for example, not allowing letters in the telephone field. Allow adding multiple addresses. • Option to modify / update the profile. • A home for the app with the latest promotions information (could be configured to show all promotions in a scroll-down) • A view to choose one or more promotions, as well as the ability to view the complete catalog of products and direct to the order section for any of these options. • An accumulation of products to total the value of the order (payment function is not included) to record and send the order. • Include a function to limit the order reception time (optional). • Allow to accumulate in the same order regular and promotional products. • Accumulate points per purchase with the function of accumulating them for consultation at any time. Likewise, allow redeeming points for one or more prizes from a catalog of prizes. Allow grouping this process in a similar way to an order so that the administrator has knowledge of what prizes should be awarded • A Devilvery profile with a view for the delivery of orders with the option to update the status of Delivered / Undelivered with a field for observations. These notifications should reach the client to the app. • Allow to address, according to the delivery address, each order to one of the two headquarters of the company. It has views (mockups) Thank you