Apple's App Store pages have Facebook like on them, which is what more could you ask or in terms of knowing what your friends do because the Facebook like button is ubiquitous. Apple needs an actual solution to this, but it is worth pointing out that they've got that Facebook thing integrated there. Do you remember ever seeing let alone clicking on the little like button on the App Store? I have seen them. They added them, I think even in iOS 6, those have been there for a while. However, maybe just me and my circle of friends, I've never seen more than one or two likes there,. And I'm not really accustomed to ignoring Facebook embed things all over the web