Dev:CFNotificationCenter

CFNotificationCenter is an object representing a local or remote notification center, which is a singleton object of its type that receives notifications from different sources, and distributes them to the listeners.

Great way to determine various PRIVATE events that may want to subscribe to
Add the observer below in your app startup code and implement the callback handler below. Then perform actions on your phone or other apps and log the events you may be interested in.

And the callback:

Hat tip: http://stackoverflow.com/questions/3725234/nsnotificationcenter-trapping-and-tracing-all-nsnotifications/3738387#3738387

Look up all observers of the local center
You can get the dictionary of all observers in the local center by doing this:

Post notification with objects
DistributedCenter has been silently available since iOS 5. It can send property list objects(NSArray, NSDictionary, NSNumber, NSString, NSDate and NSData) to other processes.

You can check if DistributedCenter can be used: