Most notable is the feature in iOS8, where any Apple device can accept a call, initiate calls, and act as a speakerphone for an iPhone, no matter where it exists “in the house”. In other words, it will pipe all the critical phone data over data networks.
Hence, one can easily see that this lays the technical groundwork for allowing a SMALLER device than an iPhone - like a wearable, like a watch - to do the same exact thing.
I’ve long thought that we’ll eventually have a wearable/carryable network, all connected by Bluetooth or something similar.
Earpiece/mike to talk and listen.
Watch as primary control.
Phone in pocket as primary storage and data manipulation device.
Pad (dumb version) as simply a larger and therefore easier to work with form of the phone screen for input and output.
Notebook computer, probably with large monitor when needed, to do intensive work.
But everything, or almost, is carried in your phone, which is the core of the system. You have it with you always. The other components just make it easier to input/ouput.
This will of course only be usable up till we get direct neural feed and implanted chips.