Android APIs
Added in API level 18
package

android.service.notification

Classes

NotificationListenerService A service that receives calls from the system when new notifications are posted or removed, or their ranking changed. 
NotificationListenerService.Ranking Provides access to ranking information on a currently active notification. 
NotificationListenerService.RankingMap Provides access to ranking information on currently active notifications. 
StatusBarNotification Class encapsulating a Notification.