The Daily Digit today is 3, as in 3-years-old. That's the ripe age of Angry Birds, a video game that has become a global phenomenon since its launch as an app on Apple's iPhone back in December 2009. In the game, players use a slingshot to attack pigs who steal the birds' eggs. From the get go, Angry Birds has remained at the top of gaming charts, reaching 200 million monthly users by the end of 2011, racking up $100 million in sales. Downloads hit a billion in 2012.