Interprocess Communication Between iOS Apps and Extensions

MMWormhole is a unique approach to implement interprocess communication between an extension and its containing an extension. The magic is done via messages written to files in the application’s shared App Group.

Using CFNotificationCenter:

“…interested parties can listen and be notified of these changes on either side of the wormhole. The effect is nearly instant updates on either side when a message is sent through the wormhole.”