Unleash the hounds: Hearthstone was the 12th highest-grossing iPad game worldwide in April

Mobile gamers have already turned Blizzard’s first iPad game into a big hit.

Hearthstone: Heroes of Warcraft, the collectible card game that has players facing off against one another in head-to-head battles, was the 12th highest-grossing app for Apple’s tablet device last month worldwide, according to industry-tracking firm Distimo. That’s despite the game only debuting globally on April 16. While the U.S. was the top-spending country for the card battler, it is really an international success. Hearthstone not only represents Blizzard’s first foray into mobile but also into the free-to-play business model, and it’s already paying off.