This interactive concept map, developed by Mark Morton in UW's Centre for Teaching Excellence, categorizes iPad apps into four kinds, and provides examples or recommendations for each kinds.
from the site: "VisualComplexity.com intends to be a unified resource space for anyone interested in the visualization of complex networks. The project's main goal is to leverage a critical understanding of different visualization methods, across a series of disciplines, as diverse as Biology, Social Networks or the World Wide Web. I truly hope this space can inspire, motivate and enlighten any person doing research on this field."