iOS technology layers

Topmost is the cocoa touch layer, which made up of several frameworks:
- UIKit : control app launching and termination. Control interface and multitouch event. Provide access to media data like photo library and accelerometer.

- Map Kit : enable developer to add google map views to their application

- Game Kit : provide mechanism for creating and using peer-to-peer networks.

- Message UI/Address Book UI : enable email compositions and contact access from application

- iAd : provide advertising interaction.

The layer underneath are media layer, core service layer and core OS