Spore

Last post of today. This is one of those games that really makes the App Store good. $7 for the full one and there's also a free one. The full version is 80mb. If you don't know what Spore is, you create an organism, and through eating other animals, you evolve (sorry creationists). You can choose your character's appearance from the start and as you add evolution points to get horns and claws.