Data processing functions and user authentication. C#/Xamarin.forms (windows/ios/Android/OS X)

Hello, We are looking for an experienced C#/Xamarin coder who can do this project for us. This will be a C#/Xamarin forms application that needs to run on a windows desktop/Android/IOS/OS X. The application involves user authentication and data processing functions. The project is well defined down to the logic level. I will send a detailed, step-by-step block diagram once your bid is under consideration. If you are an experienced C#/Xamarin coder with high rating, good work ethic, eye for detail and sound coding practices please apply. I am not looking for the lowest cost coder I can find. I am willing to pay up for high quality work done right. I will offer bonus over our agreed amount and additional work for job well done. Thank you for biding and good luck.