Close to half of the U.S. online population has downloaded an app to their mobile device according to a new survey conducted by Frank N. Magid and Associates on behalf of the Application Developers Alliance. Sixty-percent of the U.S. online population owns app-capable mobile devices--74 percent of those consumers use mobile apps, but only a quarter have paid for an app. The survey adds that a third of users plan to use apps more often and about a third of non-app users say they are likely to begin using apps within the next six months.