IPhone 3GS not implemented the HSUPA protocol). It was released in the United States, Canada, and six European countries on June 19, 2009, in Australia and Japan on June 26, and internationally in July and August 2009. The iPhone 3GS runs Apple's iOS operating system. It was succeeded as Apple's flagship smartphone in 2010 by the iPhone 4; however, the 3GS continued in production until September 2012 when the iPhone 5 was announced. The iPhone 3GS was made available for pre-order on June 7, 2009 and released on June 19 in the United States, Canada, and 7 European countries, and on June
IPhone on the O2 network in the United Kingdom, however, can buy the phone online and activate it via iTunes as with the previous model. Even where not required, vendors usually offer activation for the buyer's convenience. In the US, Apple has begun to offer free shipping on both the iPhone 3G and the iPhone 3GS (when available), reversing the in-store activation requirement. Best Buy and Walmart will also sell the iPhone. The iPhone's operating system is designed to only run software that has an Apple-approved cryptographic signature. This restriction can be overcome by "jailbreaking" the phone, which involves replacing the