Cork board type app that allows students to organize research or a project on their ipad. The free version allows for one board. Online, collaborative version would be Wallwisher
"FreeSpeech is a communication tool based upon research in augmentative and alternative communication (AAC) and human-computer interaction, as well clinical insight and expertise in speech and communication disorders." This free app could also be used to support early readers.
This is a great blog post from edSocial Media regarding using apps as sources. As more schools move towards iPad integration programs, this is increasingly going to be a challenge.
This is a great app for students doing field research. Not only does it help identify a leaf, but it also puts a variety of information at students fingertips.