qController/qController.Standard/App.xaml

<?xml version="1.0" encoding="utf-8"?>
<Application xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="qController.App">
	<Application.Resources>
		<!-- Application resource dictionary -->
        <OnPlatform x:Key="qfont" x:TypeArguments="x:String">
            <On Platform="Android" Value="qfont.ttf#qfont" />
            <On Platform="iOS" Value="qfont" />
        </OnPlatform>

        <OnPlatform x:Key="MaterialFontFamily" x:TypeArguments="x:String">
            <On Platform="iOS" Value="Material Design Icons" />
            <On Platform="Android" Value="materialdesignicons-webfont.ttf#Material Design Icons" />
        </OnPlatform>

        <Style TargetType="Label"
               Class="QFont"
               ApplyToDerivedTypes="true">
            <Setter Property="FontFamily"
                    Value="{StaticResource qfont}" />
        </Style>

        <Style TargetType="Label"
               Class="PrimaryText"
               ApplyToDerivedTypes="true">
            <Setter Property="TextColor"
                    Value="{DynamicResource PrimaryTextColor}" />
        </Style>

    </Application.Resources>
</Application>