Notifications
Notifications help you stay on top of important data. If you subscribe to a report or report view, you are notified every time your subscription is delivered. If you view saved output and you want to know when there's a new version of the report, you can subscribe to it.
The Subscribe option is available in view mode of a saved output version
of a report when you tap the More button in the application bar.

If you request notification and then someone runs that report, you get a notification with a link to the updated version.
When you subscribe, if you choose the Save the report on the system
delivery option, you receive a notification with a link to the new report version. To see all your
notifications, tap the Notifications icon in the application bar.
When yo revive a new notification, a number is added to the icon
.
For more information, see Subscribing to reports.