Angry Birds is a puzzle video game developed by Finnish computer game developer Rovio Mobile that started the Angry Birds franchise. Inspired primarily by a sketch of stylized wingless birds, the game was first released for iOS and Maemo in December 2009. Since that time, over 12 million copies of the game have been purchased from the iOS App Store, which has prompted the company to design versions for other touchscreen-based smartphones, most notably those using the Android, Symbian, Windows Phone and BlackBerry 10 operating systems. The series has since expanded to include titles for dedicated video game consoles and for PCs. A sequel named Angry Birds 2 was released on July 30, 2015.