Kids Toys by Marc Didillon is a great app for kids of a wide variety of ages. Kids Toys by Marc Didillon has coloring, numbers, adding, subtraction, division, multiplication, puzzles, and even a camera app to color on. You can also choose an “avatar” for each child.
I created one for myself and my 3 year old, but my 9 year old likes the app too!
As usual, we recorded a video, but it was hard to get my 3 year old to just show the app. She likes playing it so much. It is well worth the asking price and Marc is a great guy (and uncle!). We are not related, but I can tell from my conversations with him that he likes kids and his app shows that he understands them well.
Be sure to play the credits after you buy the app–if you can pry it out of your child’s hands! Wait until they fall asleep with your phone and then play the credits.
Marc let me know that I had set my 3 year old to “hard”. I blame my 9 year old for doing that 
Anyway here is a new video with my 3 year old solving a puzzle a little more appropriate for her age
Fun – 5
Learning – 5
Attention – 5
Total – 15!
Ages 3 – 10 (really the math portion was challenging for me at some parts).