Azure notification hub can be used to send push notification to your client app. It supports sending push notification to application build with Xamarin (but not only restricted to it). I create a notification hub in Azure using FREE TIER for a work related project, with intention to be used by team to work and test push notification in their application development. Development environment setup gave assumption that the usage will be quite less so free tier will suffice the need here. When you install the application (the one which has integrated Azure Notification Hub) on first run application will register the device with the Azure notification hub service (based on permission available) and that will count against "Active Device" in your hub server statistics. Last night, team member complained that he is now getting: 'The remote server returned an error: (403) Forbidden.'.', Exception=System.Net. » Read more