Recommend technologies we use for App development in .net

Question

For app development to use .net.

 

I think there are two main ways to do:

1.Xamarin

2.no Xamarin, means

 

            (for Example 1.background:a service(EF,linq,webapi; wcf; or so on)) 

                                    2.front end     :a UI         (Html5,or so on) 

 

Can anyone give more suggestions that the technologies in .net we will use for App development.

 

Very appreciate your help!