Example of popup in Xamarin.Forms applications. - http://julianocustodio.com/popup

PopupView.xaml

<?xml version="1.0" encoding="UTF-8"?>
<pages:PopupPage 
             xmlns="http://xamarin.com/schemas/2014/forms" 
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="DemoPopup.PopupView"
             xmlns:pages="clr-namespace:Rg.Plugins.Popup.Pages;assembly=Rg.Plugins.Popup">
    <StackLayout Margin="18"
                 Padding="36"
                 HorizontalOptions="Center"
                 VerticalOptions="Center"
                 BackgroundColor="White" 
                 HeightRequest="100"
                 WidthRequest="300">
        <Label Text="Hello Xamarin.Forms!" HorizontalOptions="Center"
                 VerticalOptions="Center"/>
    </StackLayout>
</pages:PopupPage>