Mobile computing has evolved significantly over time. Early computers required being tethered to a desk but laptops allowed for more mobility. In 1999, BlackBerry introduced the first smartphone combining PDA and email functionality. While initially adopted by businesses, over 50 million BlackBerry devices have now been sold worldwide. The iPhone launched in 2007 and popularized touchscreen smartphones, with almost 100 million units sold. More recently, the iPad launched in 2010 and pioneered the tablet form factor, selling over 300,000 units on its first day and projected to sell 28 million by the end of the year. This explosion in mobile device usage has transformed computing into a truly mobile experience.