Write an inventory Mobile application

Write an inventory Mobile Application in Xamarin using Visual studio 2015. - Search, update, insert inventory item using specific search string. - Create REST webservice vb.net 2015 management solution for the app to comunicate with SQL server and reply to search query, update, insert item. - include barcode scanning option using phone camera for upc(barcode) entry. - include setting to check if app is connected to wifi or data. - Code must be commented and be able to explain and expand in future updates. - create interface for Android, iOS, Windows. - This is a startup project, that will start within budged and can add features in the future at an hourly rate. - Please only bid within budget, No high bids please.