Xamarin documentation
Xamarin lets you build native apps for Android, iOS, and macOS using .NET code and platform-specific user interfaces. Xamarin.Forms allows you to build native apps, with shared UI code written in C# or XAML.
Xamarin.Forms cross-platform
Get started with Xamarin.Forms
Build cross-platform Android & iOS apps using C# and .NET in Visual Studio on Windows and macOS.
Build your first app
Follow a tutorial
Leverage existing knowledge
Xamarin.Forms common tasks
Important concepts for building Android & iOS apps with Xamarin.Forms