Cross-Platform Xamarin.Forms Mobile App with social networks integration

We are searching for a freelance developer/company who can bring us good quality, clean and simple source code in a scrum-spring basis for a project with open requirements and growing functionality. Estimated duration: 2 months for the first beta version. 6 extra months next year. Technologies and expertise required: - [login to view URL] - C# - XAML - PCL - MVVM - JSON - REST WS - Facebook and Twitter API's integration - UI Design experience will be aprecciated. (NOT mandatory) Source code must run into Visual Studio 2015 and include IOS, Android and UWP platform's projects. Functionality may be written in PCL and be common for all the three platforms. No platform-dependant injection required. Functionality and screen flow will be very simple: XAML forms showing REST services retrieved data, requesting some user interaction for the data and sending new REST services request with the user's response. (REST Services development are out of scope, they are done in house) TIME is not fixed, could be adapted to developer availability and "other prjects demand peeks".