The iPhone was developed by Apple as a next-generation iPod, mobile web browser, email client, and phone. It launched in 2007 with AT&T as the exclusive carrier partner in the US. Apple's strategic intent was to be the early mover in the smartphone category and capitalize on the market before competition increased. Key differentiators included the multi-touch interface, large high-resolution display, integrated apps and Safari browser, and stylish design. Apple priced the iPhone aggressively and expanded it rapidly internationally to achieve strong early sales and market share.