Windows 10 Universal Font Icons
2015-10-11Finding Windows 10 Universal font icons and viewing them visually can be difficult to locate. This page provides a list of fonts (and their symbols) and guidelines for using the Segoe MDL2 icons for Windows 10 Store Apps.

A Styles/FontSizes.xaml entry might look something like -
<x:String x:Key="DefaultFontFamily">Segoe WP</x:String>
C# example code I am using with a Navigation Pane -
Nodes = new ObservableCollection<NavigationNode>();
var resourceLoader = new ResourceLoader();
Nodes.Add(new ItemNavigationNode {
Title = @"My Cool App",
Label = "Home",
FontIcon = "\ue10f",
IsSelected = true,
NavigationInfo = NavigationInfo.FromPage("HomePage")
});
}
If you work mostly offline (like I do), you can always pull up Windows Character map and select Segoe MDL2 Assets -
See that U+E001 value? That translates to - FontIcon = "\ue001"
