Great game for your ipad/iphone, and it's on sale
for .99, usually $4.99. It's a card game where you build your deck as you play getting more powerful heroes and relics as you go along with the goal to have the most points at the end of the game by defeating monsters and aquiring cards worth lots of points. It has elements of Magic draft and was designed by some former Magic pro tour champion players, but you get all the cards you need to play with the .99 purchase.
There is a review here
that explains it better than I would.