Hearthmind isn't quite controlled the same way Twitch Plays Pokemon is though, as players vote on actions in the game by dragging their mouse cursor over the playing field as opposed to entering commands in the stream's chat. An action is picked by the game every five seconds, so it retains a somewhat brisk pace compared to its Pokemon-based counterpart. As of this writing, the stream, powered by Hitbox as opposed to Twitch, is hovering around 100 participants.
Hearthstone just launched on iOS for free this month after Blizzard detailed the game's single player campaign. An Android port of the game is still in the works.