Gone are the days of mindless bird-flinging and fruit-slashing on your iPhone. The App Store is now home to a plethora of challenging games that will put your skills to the test.From smart puzzle games that defy logic to roguelikes that turn mistakes into lessons, there is something for every type of gamer. Whether you enjoy tactical strategy, deckbuilding, or simply staring at a screen in bewilderment, there is a game out there for you.For those who relish the thrill of a challenge and don't mind losing a little before emerging victorious, here are 8 games that are worth a download onto your phone.