Angry Birds (video game) featured app on the UK App Store in February 2010 and quickly reached No.1 there, it reached the No. 1 spot on the paid apps chart in the US App Store in the middle of 2010 and then stayed there for 275 days. The initial cost to develop "Angry Birds" was estimated to exceed €100,000, not including costs for the subsequent updates. For the iOS version, Rovio partnered with distributor Chillingo to publish the game to the App Store. Chillingo claimed to have participated in final game polishing, such as adding visible trajectory lines, pinch to zoom, pigs' grunts, birds'
Angry Birds (video game) spot on the US App Store a few weeks later, where it remained until October 2010. Since release, the free, limited version of "Angry Birds" has been downloaded more than 11 million times for Apple's iOS, and the full-featured paid version has been downloaded nearly 7 million times as of September 2010. The Android version of the game was downloaded more than 1 million times within the first 24 hours of release, even though the site crashed at one point due to the load, and over 2 million downloads in its first weekend. Rovio receives approximately US$1 million per month