Here at Android Police, we've made our position on the prevalence of free-to-play mobile games perfectly known, to wit: most of them suck. It often seems like instead of embracing the audience-widening possibilities that the phrase "free game" implies, developers and publishers use it as an excuse to design games around compelling in-app purchases for more and more fleeting rewards. The phenomenon is well-documented, so I won't bore you with the inherently manipulative methods of most F2P games - you can read here and here if you really need a refresher.
Blizzard is a game developer and publisher - maybe you've heard of them. They're responsible for little series like Diablo, Starcraft, and World Of Warcraft, among others. The company's latest effort is an online, multiplayer trading card game called Hearthstone, currently in an invite-only beta on PC. Polygon reports that at the annual BlizzCon in Anaheim, California, the company announced that Hearthstone will be released on Android in 2014.
Hearthstone is loosely set in Blizzard's Warcraft franchise, hence the subtitle "Heroes of Warcraft." Like other collectible card games, it's being built from the ground up on the free-to-play model, though reports from early beta players indicate that it's still easy enough to get into the main game without spending money.
Blizzard's franchises have so many followers that someone could fill a conference building with legions of fans and throw a party in their honor. Actually, such an event already exists. Blizzard hosts BlizzCon every year and invites thousands of players to come celebrate WarCraft, StarCraft, and Diablo. It lasts for two days, but considering how many hours conference goers have already invested into these titles, this amounts to little more than another quest.