The Pew Research Center's Internet & American Life Project has released The Rise of Apps Culture.
Here's an excerpt:
The most recent Pew Internet Project survey asked a national sample of 1,917 cell phone-using adults if they use apps and how they use them. Broadly, the results indicate that while apps are popular among a segment of the adult cell phone using population, a notable number of cell owners are not yet part of the emerging apps culture.. . .
Of the 82% of adults today who are cell phone users, 43% have software applications or "apps" on their phones. When taken as a portion of the entire U.S. adult population, that equates to 35% who have cell phones with apps. . . .
Yet having apps and using apps are not synonymous. Of those who have apps on their phones, only about two-thirds of this group (68%) actually use that software. Overall, that means that 24% of U.S. adults are active apps users. Older adult cell phone users in particular do not use the apps that are on their phones, and one in ten adults with a cell phone (11%) are not even sure if their phone is equipped with apps.