Apple had a mixed year in 2011. Jobs's resignation raised questions about whether or not the company could maintain its leadership role in the mobile market. But the company has seen enormous growth due to some shrewd business moves and compelling products.
One big change for Apple in the United States was the announcement that the iPhone would become available on Verizon Wireless's network. Previously, only AT&T carried the iPhone in the United States. Out of the four major cell phone carriers in the United States, Verizon has the most customers -- AT&T is in second place. Suddenly, Apple had access to millions of new customers.
By the end of 2011, the iPhone would also come to Sprint's network, leaving T-Mobile USA as the only major network in the United States without an iPhone. Apple also launched the iPhone 4S. The new iPhone sports the same basic exterior design as its predecessor but includes more features, including a virtual assistant called Siri that uses voice-recognition software built in to the device.