Fun math for a child

For my eldest daughter (6 years) I made an application on android for studying mathematics (this is really my first experience :clown: )
https://play.google.com/store/apps/details?id=com.Flystar.MathKids
What do you think about it. What you need to change, delete or add :hi5:

Great thanks

I use Primer a lot more than I thought i would. Its an iphone app that prime factorizes any number you put into it (to a point, of course). Very useful and simple