How do I develop native Mobile apps in Blazor?

You can develop a native mobile app in Blazor using Experimental Mobile Blazor Bindings. This allows developers to develop mobile applications in C# and .NET for iOS and Android. It uses Razor syntax to define UI components and the underlying UI components are based on Xamarin.Forms native UI Components. Currently, it is in an experimental mode. 
Check this link to understand the concept: Mobile Blazor Bindings