For $258 we could get 21 issues of National Geographic Explorer for the ipad (for each of our 20 ipads in the smith cart) - with 7 K-1 issues, 7 2-3 issues and 7 4-6 issues (also can be used for higher readers in 2-3). Much more cost effective then ordering paper copies, and a great way to make digital literature available in all K-5 classrooms.
App is very interactive and connections to grade level science content occur often.
http://magma.nationalgeographic.com/ngexplorer/pioneer/
Looks good, kids would really love it. I would be willing to help pay the costs with some of my budget. Could use the content to address the ELA common core science standards.