Number 8 in Tinybop’s Explorer’s series, Space should more accurately be called "Hands On With the Solar System." After you create a rocket, you blast off on a mission to visit each planet. Each planet offers different sets of tests. There's a cross-section viewer so you can see the insides, and a snowman that you can drag and drop to the surface to test the temperature. You can see how gravity works by throwing a huge bolder at the planet, and objects on the screen can be labeled with a toggle on/off, which are available in many languages.

There are several ways to navigate -- a fact that makes this app confusing at first, but also increases the chance you'll stumble into something interesting. So you can call this "good confusion."

We especially liked the distance calculator and the way you can compare the time of each planet orbit, relative to the earth. Nice touches include the planet size comparison tool, and close up view of Jupiter's spot. It helps you understand that on the relative scale of the universe, we're all pretty tiny. Kids can discover new worlds in other Explorer’s Library apps, including The Human Body, Plants, Simple Machines, The Earth, Weather, Homes, and Skyscrapers.

Art by Jessie Sattler.The app includes a handbook that can help guide teachers or parents as they talk through Space concepts with kids.