I added the mobile centre SDK to my xamarin forms app and then added the below in App.xaml.cs:
MobileCenter.Start("ios=eab5ae24-2c21-4bc4-af8b-bdc01b41d27d;" +
"uwp=08df195d-1f0d-42db-bf5c-70de451d9e3a" +
"android=fab0066e-af9a-494f-b677-b231cfec53b9",
typeof(Analytics), typeof(Crashes));

It works well in iOS and Andriod but results in the below error in UWP:

System.MissingMethodException occurred
HResult=0x80131513
Message=Method not found: 'System.Runtime.InteropServices.WindowsRuntime.EventRegistrationToken Windows.ApplicationModel.Core.CoreApplication.add_LeavingBackground(System.EventHandler`1<Windows.ApplicationModel.LeavingBackgroundEventArgs>)'.
Source=
StackTrace:
at Microsoft.Azure.Mobile.Utils.ApplicationLifecycleHelper..ctor()
at Microsoft.Azure.Mobile.Utils.ApplicationLifecycleHelper.get_Instance()
at Microsoft.Azure.Mobile.MobileCenter.InstanceConfigure(String appSecretOrSecrets)
at Microsoft.Azure.Mobile.MobileCenter.StartInstanceAndConfigure(String appSecret, Type[] services)
at Microsoft.Azure.Mobile.MobileCenter.PlatformStart(String appSecret, Type[] services)
at Microsoft.Azure.Mobile.MobileCenter.Start(String appSecret, Type[] services)
at TILL.POS.App.OnStart() in C:\Source\Till-POS\2.Clients\TILL.POS\App.xaml.cs:line 199
at Xamarin.Forms.Platform.UWP.WindowsBasePage.LoadApplication(Application application)