One year ago, less than 40% of mobile subscribers in the United States had a smartphone. That number has increased dramatically, however; according to Nielsen, one in two mobile subscribers now owns a smartphone. Driven mostly by the rise of Android and iOS, which account for more than 80% of the U.S. smartphone market, 2012 has turned into the year of the app. The average number of apps installed on each smartphone has jumped 28% in 2012, an increase from 32 apps to 41. Smartphone owners are also spending increasingly more time using apps than using the mobile web, roughly 10% more than last year. Nielsen notes that the top five most active apps continue to be Facebook, YouTube, Android Market (now Google Play Store), Google Search and Gmail. Despite the increase of apps, smartphone owners spend roughly the same amount of time using them each day â€” 37 minutes in 2011, compared to 39 minute in 2012.