Once you get your first toast notification it will be added to the list of apps in the notification center. So it'll take a couple of time before you see can adjust the parameters to all your apps on there. But at least by default they appear in the notification center, so just wait for a notification and once you receive one you can then modify the app settings if you want to disable notification, or sounds or whatever. But you need to make sure first that the toast notifications are enabled in the app itself.