UPDATE: iOS app privacy

How does a Google or Microsoft iOS app know that I have other Google or Microsoft apps installed on my iOS device?  For example, if I download and install Chrome (after having, perhaps Google Maps installed and myself logged in), I am greeted with to offer to sign in - and Chrome already knows my Google ID.  Similarly, if I download Word, log-in, and then download Excel, Excel already knows my Microsoft ID.

This is surprising as it means the apps have access to both a list of my existing apps (I think this is okay but not ideal) as well as my user ID (huh?).  Is it possible for me to write an app that can: (i) determine a user's Google ID; and (ii) ask the user to log in and thus give me credentials?  (i) alone seems bad, (ii) is very bad.

Also, noting that I do not even need to provide a password to confirm to Chrome that I am myself, is there some serious security lapse here?

All very odd

UPDATE: Is this related?  http://appleinsider.com/articles/15/06/24/apple-expanding-user-privacy-will-prevent-ios-apps-from-seeing-other-installed-apps.  It's not completely the same (as this seems narrower than knowing my Google ID and Microsoft ID).  But perhaps part of the same framework?

Apple and high defensibility

There are lots of reasonable questions about iPad's growth and future.  Nevertheless, this article makes a nice argument that Apple has enough of a lead in the space and, more importantly, a sustainable advantage in processors, to continue to earn profits and improve the product without obvious near-term risks or competition in its high end space.  This is a direct result of Apple's vertical integration and, as a corollary, having a proprietary source of supply for chips.  Whether or not there is some enormous use case of the iPad is still somewhat unknown (to be clear, it is a big business even if people have difficulty articulating exactly why it is better than alternative formats), at least there is time for Apple, its customers, and its developers to figure it out.

Even more interestingly, the article notes that this processor independence makes a strong case for AppleTV and AppleWatch.  In brief, as Apple works to bring general computing to different places, it can stake out a high and differentiated ground using hardware (processor) and software (OSX/iOS) advantages unlike anyone else.  It is not the idea of vertical integration as a defensive strategy that is interesting; it is the fact that no one else seems to be trying this (at least successfully).