Android/iOS: My Incredible Body is a free, high-quality app with an interactive tour of the human body, which is educational for kids and probably their parents too. The animations are high quality and the app teaches about each part in a way that's easy to understand.
Zybright's app teaches children about the anatomy of the human body in a way that's fun and informative. A 3D rendering lets you switch individual elements of the body on or off, such as the skeleton, the nervous system, muscles, the heart and its arteries, etc. Kids can also tap each element to learn about them, and watch guided video tours that take them through the body.
It's one of the best educational apps for kids, especially when you consider that other apps like this are paid.