Ages: 5 and up
What it teaches: Math (Operations, Counting and Reasoning, Logic Games)
Why I recommend it: Math Doodles presents three math games (with one more on the way) for kids to stretch their mind applying value and quantity. Unlike many other math apps, this one really gets you thinking while being very supportive to decrease frustration. Kids are given a tremendous amount of choice, both in the ways numbers are represtented (dice, fingers, roman numerals!) and how they can easily move between difficulty levels as needed.
Available here, 2.99*