The iPhone seems obvious and its success assured now – but as recounted in Fred Vogelstein's forthcoming book Dogfight, it was actually a tightrope walk involving barely ready prototypes, buggy software and last-minute deals. When Jobs showed off the iPhone in January 2007, there wasn't an assembly line for them, and Jobs's demos had to be carefully planned to avoid embarrassing crashes using a "golden path" worked out laboriously by testers.