You can activate the back button easily like this:
using Windows.UI.Core;
var currentView = SystemNavigationManager.GetForCurrentView();
currentView.AppViewBackButtonVisibility = AppViewBackButtonVisibility.Visible;
Please note, that the back event is handled with the BackRequested
event on the same view:
currentView.BackRequested += // Event handler goes here
Please note: The back button is only displayed in the title bar, when the app is running in desktop mode. When the app is running in tablet mode, the back button is moved to the Windows task bar (bottom left).