An iOS device feels like the perfect fit for a collectible card game: An iPhone is about the size of a card, and an iPad screen is big enough to display a series of dealt hands. Plus, who wouldn't want to give up on the hassle of accumulating real-life paper? Finding good collectible card games among a sea of iOS games on offer can be quite the daunting task, especially given how many CCGs turn out to be boring, unrelenting cash-ins rather than innovative games that revolve around complex strategic concepts. Here's a roundup of the greats.