As a 2nd grade teacher in Math, I have tried Raz-Kids and Beestar for my students for their independent learning time. Beestar provides more test practices for students that allow them to be more prepared for school tests. I also recommended my co-workers and parents to use Beestar.
This site is GREAT for my daughter who is home schooled and has difficulty with reading, comprehension, and retention. It make my job so much easier! LOVE the site!
Answer: All kinds! Just choose your level. Level aA is the lowest so that's where the most easy books are. Level Z is the highest, so that's where the hardest books are. Although I would recommend to give Raz-Kids to kids who are still in elementary school and not secondary or higher.
Raz-kids has a rating of 1.9 stars from 26 reviews, indicating that most customers are generally dissatisfied with their purchases. Raz-kids ranks 149th among Kids Educational Resources sites.