WordCub Letters and Sounds has been helping me out in that department. It's a simple, customizable iPhone app - created by a mom who also happens to be a teacher and her husband who happens to be a developer - that teaches basic phonics concepts in short bursts to my almost-five-year-old. And it's been a lifesaver for me on more than one occasion.
Children can touch, tap and swipe their way through a series of little alphabet block pictures and get a reward mini-game at the end of each set. All the while, they're learning basic concepts of reading and you're learning that, hey, maybe you should let your kids watch TV and play iPhone games all day because, man, this house sure is peaceful. Or maybe that's just me. -Stephanie



