iPad (// EYE-pad) is a line of tablet computers designed and marketed by Apple Inc., which runs Apple's iOS. The first iPad was released on April 3, 2010; the most recent iPad models, the iPad Air and second generation iPad Mini, were revealed on October 22, 2013 and went on sale November 1, 2013, and November 12, 2013, respectively. The user interface is built around the device's multi-touch screen, including a virtual keyboard. The iPad has built-in Wi-Fi and, on some models, cellular connectivity. There have been over 170 million iPads sold since its release in 2010 (as of October 2013).