Math Bumpies HD - Adventure on Math Island: Addition and Subtraction (free, ages 4+) A simple and fun app for your child to pick a character and solve problems along the way. it is an interactive game that shows children how to add and subtract

for Ipad-

http://www.gamespot.com/math-bumpies-hd-adventure-on-math-island-additi/

Kid Numbers and Math (free , all ages) An app for all different levels of learning. The problems go from simple to complex and will teach subtraction and addition.

for Android-

https://play.google.com/store/apps/details?id=zok.android.numbers&hl=en

Addition & Subtraction for Kids (free, ages 4+) A fun and interactive game that uses animals to add and subtract. This would be a fun app to play and learn!

for Ipad-

https://itunes.apple.com/us/app/addition-subtraction-for-kids/id426907035?mt=8

Mad Math 4 Kids (free, all ages) This is a fun app to show children addition and subtraction facts that are fun and interactive using puzzles. Your child will learn about adding and subtracting.

for Android- https://play.google.com/store/apps/details?id=air.com.zoki.madmathkidsfree&hl=en