What can I put into the blue area at top of app?

There's a blue rectangle above my first control in my pages. My question is whether I can put things, for example a menu or picture. Also, what is this are called? Here, the Xaml for my opening page (the blue rectangle is above the label with the text "Welcome to Rodney Pix":

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:TestXamarinFormsProject"

         x:Class="TestXamarinFormsProject.MainPage">

<ScrollView>
    <StackLayout  x:Name="sl" Orientation="Vertical">
        <Label Text="Welcome to Rodney Pix" HorizontalOptions="Center"
       VerticalTextAlignment="Start" VerticalOptions="Start"></Label>

        <ListView x:Name="lstDirectories" ItemTapped="LstDirectories_ItemTapped"
                  SelectedItem="{Binding SelectedListItem,Mode=TwoWay}">
            <ListView.ItemTemplate>
                <DataTemplate>
                    <ViewCell>

                        <StackLayout Padding="5" Orientation="Horizontal">
                            <Label Text="{Binding FriendlyDirectoryName}" TextColor="Black"/>
                        </StackLayout>

                    </ViewCell>
                </DataTemplate>
            </ListView.ItemTemplate>
        </ListView>

    </StackLayout>

</ScrollView>