Project Purple was a top secret project by Apple that took place in 2004/2005 which eventually became the iPhone. In 2004, Steve Jobs conceived an idea of using a multi-touch touchscreen to interact with a computer in a way he could type directly onto the display, essentially removing the physical keyboard and mouse. The device would be a phone with an integrated music player, operated by the touch screen. Jobs recruited a small group of Apple engineers to investigate the idea and codenamed it "Project Purple". In February 2005, Steve Jobs gave the team an ultimatum: two weeks to show progress with the operating system, or have the project assigned to another group. Greg Christie, an engineer working on the project at the time, commented: "Steve had pretty much had it, he wanted bigger ideas and bigger concepts."

The software team came up with several features that would end up in what's known today as iOS, including the "slide to unlock" feature, placing calls from the address book, the touch-based music player, the bounce back effect when reaching the end of a page, or the conversation view of SMS messaging. The team literally 'banged their heads against the wall' over how to change text messages from a chronological list of individual messages to a series of separate ongoing conversations.

For months, the engineers made presentations every other week to Jobs in a windowless room where only certain Apple employees had access. Not even cleaning personal had access to the room. And Jobs had strict requirements for at-home work as well, demanding that employees involved in Project Purple use a computer in a secluded part of the house to prevent anyone from accidentally seeing details, and encrypt all digital images related to the device.

"With each demonstration, Jobs was finally impressed. And Mr. Jobs took over more of the narration, making the story his own. His excitement for it was boundless." Christie continued.