NASA App for Android

From Android 4 Schools post:

 The NASA App for Android is a free app that gives you access to thousands of NASA videos and images. Not surprisingly, the videos are found in the “video” section of the app. The images, however, are not nearly as well organized. To view the images you need to sort through the “missions” section of the app. You will also find images in the “featured” section and the “news & features” section of the NASA App.