Going into its third year, the App Store had become successful beyond anyone - probably even Apple's - wildest dreams. It was enabling and serving more apps from more developers to more customers than any single software source in history. However, while iPhone and iPad apps were the most popular in mobile history, they were far from the most capable. That's why, in April of 2010 at the iPhone OS 4 - renamed iOS 4 shortly thereafter - preview event, Apple started amping up apps. Folders increased the raw number of apps that could be loaded onto any device at one time, Calendar access let developers hook into the event system, and iAd gave them an additional, Apple-owned option for monetizing free apps. The biggest new feature, however, for users and developers alike, was multitasking. Kind of.