Halbrick Studios is probably one of the best mobile game developers with games like Fruit Ninja and Jetpack Joyride in its portfolio. Now, it has decided to go a different direction and is currently developing a CCG called Mythic. Halbrick is trying to make Mythic strategically challenging yet fun to play (which is the goal of pretty much any CCG on mobile). The info we have is limited, but we do know the game is bringing Gods, Myths, and Legends to mobile. Expect to see characters like Loki, Cleopatra, Heimdall, and all kinds of characters from Greek, Norse, and Egyptian mythology and history.
What does seem to be different than other CCGs is how the cards are placed in boards of different shapes, a mechanic which promises a different flavor compared to games like Hearthstone. You can join the iOS beta here and the Android one here.