Well, Freelancer.com strongly hints that it may have something to do with the increased clout of Google's Android operating system. Last quarter, a whopping 152 million Android smartphones were shipped globally, enough to make Android, in the words of one analyst, "the undisputed volume leader of the smartphone industry at the present time."
And indeed, Freelancer.com does show a 7 percent uptick in listings for Android jobs in Q4, to 4,282 jobs in all.
The rise of Android doesn't necessarily mean that everyone has switched camps. It's possible that iPhone gigs gave way to jobs that require HTML5, a programming language that works on iPhone, iPad, Android, Mac, PCs, and any number of other devices. Why program for one, when an HTML5 websites work pretty much everywhere?
In related news, this week Apple release iOS 6.1, the newest iteration of its mobile operating system. Adoption has been steady, with 22 percent of all iOS devices hosting the new software just 36 hours after launch. Jason Baptiste, CEO of Onswipe (the company that published the adoption figures), told TechCrunch this probably has something to do with Apple's over-the-air software update system.