This is where Apple really adds value and why they have their own silicon design teams.

Some of the blocks:

-- M7 motion chip

-- Image processing chip to support camera

-- (I suspect) audio processing chip to do compression and feature extraction for SIRI

-- (suspect) video codec (though this may be done by GPU)

-- Secure Enclave -- CPU with secure data, random number generator, Apple Pay support, Fingerprint Sensor support

-- (I suspect) memory management units and io co-processors and the like that are too mundane to get much public mention