There is a really, really cool free app today that you can get called Highlights Hidden Pictures. Highlights Hidden Pictures™ Puzzles features all the fun of classic hidden pictures plus an expanding world of fun with downloadable puzzle packs! Thanks Money Saving Mom!
Compatible with iPhone 3GS, iPhone 4, iPhone 4S, iPhone 5, iPod touch (3rd generation), iPod touch (4th generation), iPod touch (5th generation) and iPad. Requires iOS 5.1 or later.
Go HERE to get yours!