AppBar in Windows Phone 8.1 and 8.0 app

In Windows Phone 8.1, We can use BottomAppBar to add AppBar. Usually we use CommandBar to create basic BottomAppBar. CommandBar contains two collection: PrimaryCommands and SecondaryCommands, It’s similar with shell:ApplicationBar.Buttons and shell:ApplicationBar.MenuItems in Windows Phone 8.

If you are working on a Windows Phone 8/Windows Phone 8.1 Silverlight application then use the the following XAML code.

If you need in depth details on Windows Phone 8 app bar then refer to this MSDN article.