Classify it!
This is a Science app, that test the studenst knowledge of the various organisms and how they are related to each other. The student will be challenged by knowing how the organisms should be sorted and grouped. The game has 30 level, and each level they earn creature cards which they will learn about more organisms. This app requires iOS 6.0 or later and is free on app store. It is also avaiable on Androids. This app can be used in grades 3-8.
https://itunes.apple.com/us/app/classify-it!/id911484593?mt=8