Math Ninja HD Free which is actually a game that helps students practice addition, subtraction, multiplication and division and is set up to do the game before they practice their math.
It is set up so students have the choice of three levels of difficulty, easy, medium, and ninja. In addition, the student can chose to practice problems from addition, subtraction, multiplication, or division or from all four. They also have the option to customize their choice.
Each round gets a bit harder and as long as the ninja is able to take out the robo animals, there is a chance to advance but if the students is not able to get rid of all the robo animals, they loose.
So the math facts are what help the student gain additional weapons and practice. I would say this app is good for both elementary and middle school plus possibly it could be used as remediation in high school. I think I"ll try it out to see how well the students like it.