Android is an open-source operating system designed for touchscreen mobile devices. It was developed by Android Inc, which was later acquired by Google. The first Android phone was released in 2008. There are now many manufacturers that make Android phones like Samsung, HTC, and Motorola. Android phones vary by manufacturer and carrier but share common features like touchscreens and access to the Android app market, which has over 150,000 apps. Five example Android phones described are the HTC Thunderbolt, T-Mobile G2x, Samsung Galaxy S II, Motorola Atrix 4G, and Samsung Epic 4G.