Example of Local Notification in Xamarin.Forms applications - http://julianocustodio.com/local-notification

MainPage.xaml

<?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:LocalNotificationDemo"
             x:Class="LocalNotificationDemo.MainPage">
    <StackLayout>
        <Button Text="Notification" Clicked="Start_Notification"/>
    </StackLayout>

</ContentPage>