When you think of Apple you probably think of the iPhone. But just 15 years ago, its hit product was the iPod. The iPod changed the way we listen to music and helped grow Apple into one of the biggest companies in the world. But the iPod went from accounting for almost half of Apple's revenue to not even being promoted by the company. Today, the only iPod Apple sells is the iPod touch, having discontinued the iPod Classic, Nano, and Shuffle.