Tinkercad is a free, easy-to-learn online app anyone can use to create and print models. It allows you to place, adjust, and combine shapes that can then be printed using any of the Libraries' printers.
MakerBot Launches Hands-On Learning Guide For Printing In The Classroom. This would be useful to both teachers and all students, both GT and those in need of assistive devices. This could be used for multiple grade levels.