Hearthstone: Heroes of Warcraft is a digital card game based on the World of Warcraft TCG set in the Warcraft universe. Hearthstone is a free-to-play, online card game on the Microsoft Windows, Mac OS X, iPad, and Android tablet platforms that anyone can play. Players choose to play as one of nine epic Warcraft heroes, and then take turns playing cards from their customizable decks to cast potent spells, use heroic weapons or abilities, or summon powerful characters to crush their opponent.
Hearthstone Official Site
Hearthstone Wiki