These are the ones reviewers love

If you’re about to take a long car trip with your family and you’re not looking forward to all the screaming and yelling from the kids over the six hours until you get to grandma’s house, the Amazon Fire HD 8 Kids Edition makes for the perfect tablet for children between the ages of 3-12.
Amazon has really outdone themselves with a kid version of their Fire HD 8, only this time the tablet ships with a colorful and durable “kid-proof” case that’s built to stand up to drops, throws, and all sorts of spills. Even if that’s not enough to protect the tablet, Amazon offers a worry-free guarantee for all Fire HD 8 Kids Edition purchases. Simply put, Amazon will replace the tablet with no questions asked for up to two years.
If you’re worried that your kids might accidentally access mature content, the Fire HD 8 Kids Edition runs on a limited version of Android that keeps kids away from any unauthorized websites, apps, and in-app purchases with deep parental controls and age restrictions, so you know exactly what your kids are doing with the tablet.
Amazon also offers one year of Amazon FreeTime Unlimited, which offers kids more than 15,000 books, films, TV shows, and games made just for kids. The service also includes educational apps and games featuring characters from Disney, Nickelodeon, and PBS. However, these perks expire after the first year without an Amazon Prime membership.
The Amazon Fire HD 8 Kids Edition comes in three case colors, has a 4.1 out of 5 star customer rating, and retails for $129.99. 
Amazon also offers various sizes like the non-HD Fire 7 Kids Edition, which retails for $24.99, and Fire HD 10 Kids Edition, which goes for $199.99.