iPhone is a line of smartphones designed and marketed by Apple Inc. It runs Apple's iOS mobile operating system. The first generation iPhone was released on June 29, 2007; the most recent iPhone models are the iPhone 6 and iPhone 6 Plus, which were unveiled at a special event on September 9, 2014. The user interface is built around the device's multi-touch screen, including a virtual keyboard. The iPhone has Wi-Fi and can connect to many cellular networks, including 1xRTT and GPRS, EDGE, UMTS and EV-DO, a faster version of UMTS and 4G, and LTE. An iPhone can shoot video, take photos, play music, send and receive email, browse the web, send texts, GPS navigation, record notes, do mathematical calculations, and receive visual voicemail. Other functions—video games, reference works, social networking, etc.—can be enabled by downloading application programs; as of October 2013, the App Store offered more than one million apps by Apple and third parties and is ranked as the world's second largest mobile software distribution network of its kind.