Common Sense Media Check out great apps using Common Sense Media's "Top Picks". You can also search for apps and see parent and educator reviews.
Bloomin' Apps This Kathy Shrock page has an amazing list of apps for many applications!
Edutopia Article Math App Info This Edutopia article gives an excellent overview of good criteria for selecting apps to strengthen math skills. It also names specific useful apps to use. (All Grades)