Check out the newly released Bill Nye the Science Guy free app at

https://itunes.apple.com/us/app/bill-nye-the-science-guy/id652548755?mt=8

Requirements are:  Compatible with iPhone 3GS, iPhone 4, iPhone 4S, iPhone 5, iPod touch (3rd generation), iPod touch (4th generation), iPod touch (5th generation) and iPad. Requires iOS 6.0 or later. This app is optimized for iPhone 5.