Well, smartphones have been mainstream for a few years now, and while exactly when is up for debate, the number of total applications downloaded over the week of Christmas makes it hard to deny. This isn’t particularly shocking given what we already know, but a 60% jump in a single week is very impress, and the total number of app downloads reaching 1 billion is equally impressive. Now, there isn’t any data on how many of those were purchased, but even if we assume 75% were free, thats still millions of apps purchased. It is a great time to be a mobile application developer. Source after the break below: