Clash of Clans is a popular iPad/iPhone/iPod game created by "Supercell". It has been available internationally on the iTunes store for free since it's initial v1.7 release on August 2, 2012. Clash of Clans is a strategy game where, like many other strategy games out there, the purpose is to build one's village, unlock different warriors, raid resources from other villages, create a clan and much, much more.

More information can be found here: http://clashofclans.wikia.com/wiki/Clash_of_Clans_Wiki