My Take
I would not recommend this app as it is very boring. It's the same setting over and over again. The students have to be quick and able to add in their head. The kids lose interest in this app very quickly as there is no real reward or gain in their eyes. Plus it's very monotonous.
How I Use It
This app would be used to help students to practice their addition facts. Students can add any where from 2 numbers on up. For example if they needed to get the answer of 10 they could add 2+2+2+2+2 or 5+5, etc. It's very fast paced and students lose interest very quickly as it is the same thing over and over again.