It's good, but after doing it you get easily distracted because its boring to the students. They don't like using it. I don't recommend it if used for main grade.
I didn't like it. The kids I work with didn't like it. The parents didn't like it.
How I Use It
It's used as a main grade and homework. There are 100 questions that are due end of the week. The only questions that count though are the ones that are right so no matter how many questions you answer if you didn't get 100 correct at the end of the week you lose credit.