It’s been around since 1999 and is one of the coolest sites out there for animated, engaging content. With a 100,000-member strong teacher community, BrainPop offers free lesson plans, tutorials, professional development tools, graphic organizers and best practices. Interestingly, it was conceived by an immunologist and pediatrician, Dr. Avraham Kadar, M.D. to explain difficult concepts to his younger patients. Instead of just reaching his patients, he reaches more than 8 million web visitors. Now available at iTunes and on the iPad, iPhone and iPod, BrainPop includes K-3, Spanish and ESL versions in addition to the standard version. It’s just plain loaded with content—from Science, Social Studies, English and Math to Arts & Music, Health and Technology. Click on Science and you’re just starting to scratch the surface: there’s Cellular Life & Genetics, Earth System, Energy, Matter & Chemistry and on and on. One of the best parts? Free movies! Click here—but just a warning—it’s very addictive: BrainPOP.