A funny thing happened at the iTunes App Store last week. An app called Skyfire “sold out.” This collection of code — which could theoretically be copied an infinite number of times at no cost save for that of bandwidth and electricity — was suddenly the Tickle-Me-Elmo of the direct-download software world. The cupboard was bare. The term “sold out” suggests Skyfire is in high demand, which is true. It’s not “Angry Birds” popular, but it’s in the App Store’s top 10 as of this writing. It offers something that iPhone users have never been able to get before.
