Blizzard announced on Wednesday that its free-to-play collectible card game, Hearthstone: Heroes of Warcraft, is finally rolling out worldwide for the iPad. Hearthstone has been available on the iPad in select regions for a few weeks, but April 16th represents the app’s official international launch. The app supports the 2nd, 3rd and 4th generation iPads as well as the iPad mini, Retina iPad mini and iPad Air. If you’ve somehow missed out on the explosive popularity of Blizzard’s latest title, Hearthstone is a collectible card game that offers some of the most impressive visuals and easy-to-learn gameplay in the genre. A series of tutorial battles will walk you through the nine available classes, each of which has class specific cards and a