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 5S so customers could keep checking for units available at their local Apple Stores, and order for pickup. Online orders were also in short supply on launch day, with the shipping date across all model sizes and colors changing from "7-10 working days" to "October" in all countries, within hours of online orders being taken. The iPhone 5S was the best selling phone on AT&T, Sprint, Verizon, and T-Mobile in September 2013 in the United States, outselling the iPhone 5C and Samsung Galaxy S4. According to Consumer Intelligence Research Partners, the iPhone 5S outsold the 5C by a two-to-one margin during