This app goes with the FREE service provided by littlebirdtales.com. Students can create stories with their own artwork and audio recordings either from an app or on the web. The completed tales can be downloaded as either a PDF or mp4 with audio.
This is the math app that has been featured in numerous iPad commercials. It is a great product for arithmetic drills and includes problems for addition, subtraction, and multiplication.
This article from I Education Apps Review lists out a series of apps to use for creating custom digital content. Not all are free, but the list presents some interesting options.
This free eBook is available for download and provides a great interactive resources. Each section ties into some aspect of Bloom's Taxonomy and provides additional information to support iPad integration into the curriculum.