Since the birth of the App Store and their ever popular commercials back in 2009, Apple and iOS devices have always been associated with the popular slogan "There's an app for that". It only makes sense Apple would want to trademark the slogan that made the App Store so popular. It's not just an advertising tool anymore, it's become so much more than that within our culture. I frequently joke around when someone asks me how to do something, a frequent response to any iOS device user is "There's an app for that." And normally, there is.
Apple originally filed for the trademark back in December 2009. The first use sited in their trademark application was in January 2009. The trademark will cover retail store services, computer software services provided via retail or internet, and handheld mobile electronic devices, and other consumer electronics. Basically, Apple is trying to cover all bases to make sure that consumers only associate their popular catch phrase with iOS devices and not other mobile brands that may offer similar services (i.e. - Android, Blackberry, etc..).