Hearthstone: Heroes of Warcraft is the best example of the popularity of merging video and trading card games onto smartphones. Gameplay focuses on class-specific decks that require different strategies as players summon creatures and cast spells to inflict damage on their rivals. But the smartest feature is how the developer leverages the digital medium so that Hearthstone can have cards and actions that are impossible to reproduce in the paper and ink game. Players can use a card that pulls a random beast into the field. Some creature cards can multiply under other conditions. Best of all, players don't have to worry about keeping track of the complicated math, rules and moving parts, because that's all done by computer.
RATING: 12+ (ages 12 and older)
PLOT: Rivals battle using cards, creatures and casting spells.
DETAILS: Free; compatible with iPhone, iPad, and iPod touch, requires iOS 5.1 or later.
BOTTOM LINE: Trading cards get all decked out for smartphones.