Integrated software and hardware changes support the introduction of new user interface and functions by Apple, including the voice recognizing and talking assistant calledSiri, personal computer independence, cloud-sourced data (iCloud) and an improved camera system. A selection of the device's functions may be voice-controlled.
The iPhone4S was unveiled at Apple's "Let's Talk iPhone" event on October 4, 2011 in Cupertino, California. Apple started taking pre-orders for the iPhone 4S on October 7, 2011 inseven initial countries (United States, Canada, Australia, United Kingdom, France, Germany and Japan) with the first delivery date set for October 14, 2011, and available on thatsame day for direct store sales in those countries. It was released in 22 more European, American and Asian countries, including Ireland, Mexico and Singapore on October28.
It is available on 100 carriers in 70 countries overall, including AT&T, Verizon, and for the first time, also for Sprint and C Spire customers in the United States. InJapan, it is available for au (a KDDI brand) and Okinawa Cellular, for the first time. For US customers, while pre-orders for purchasers buying contracts started on October 7,2011, unlocked (contract-free) sales started on November 11, 2011. The Associated Press said that AT&T described early iPhone 4S demand as "extraordinary".