IPhone (1st generation) $499, the original launch price of the 4 GB model. Apple released an SDK on March 6, 2008, allowing developers to create the apps that would be available starting in iPhone OS version 2.0, a free upgrade for iPhone users. On June 9, Apple announced the iPhone 3G, which began shipping July 11. The original iPhone was discontinued 4 days later; total sales volume came to 6,124,000 units. During release, the iPhone was marketed as running "OS X". The name of the operating system was revealed as iPhone OS with the release of the iPhone SDK. The original iPhone supported
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