Reference+Apps

iBooks (free) Kindle (free) Brainpop (free) This Day (free) Library of Congress (free) Merriam Webster Dictionary (free) Discovery Mobile App for Education Webclip (free) The Elements ($13.99) Wolfram Alpha ($1.99) Google Earth (free) Biblion (free)

Britannica Concise Guiness Book Epicurious How Stuff Works National Geographic StarWalk TED Wikipanion World Atlas Mashable