Hearthstone is a collectible card game, originally launched in March 2014. Ever since it was first introduced, the game's popularity has skyrocketed, to the point where it's now a major player in the e-sports scene, with the prize pool for the 2016 World Tour capping at a whopping US $1 million.
The app then is a scaled down UI for the PC game. Players are given a range of unique classes to choose from, and a set of starter cards, as well as more they can unlock through the initial tutorial levels. After that, Hearthstone throws you into the wild, letting you battle other players for supremacy. While you can spend real money to buy more cards, it's also possible to play the game for absolutely free. Battling other players wins you in-game gold, which you can use to buy card packs in the store.
Players familiar with the Warcraft game universe will find inside jokes and references galore, but Hearthstone is a game that even a complete newbie can pick up. Aside from owning the cards you believe are the best, a lot of the game is still left to chance. This means the game prioritizes strategic thinking and smart reactive plays to your opponent, as opposed to the lightning reflexes demanded by other competitive games.
Think of it as a modern fantasy take on chess, where each unit does something different. All you need to dominate is an internet connection and a cunning strategy.
