There are a number of Apps lists available to help you decide on the best Apps for use in teaching and learning. Many of them are being created in Google Docs or on Wikis as ongoing live documents that will be regularly updated.
Learning Exchange has started a list of Apps in a Google Docs as reviewed by educators across the Catholic Education Parramatta diocese. Access the list " Learning Exchange iPad App review"
Another really interesting take on the App list is this from Classroom Instruction that works (CITW), a list of educational apps categorized by instructional strategies: Apps for CITW
For Special Education:
iPod/iPad Apps for Special Education and Remediation-Feedback Google Doc list.
A well categorised website IEAR - I Education Apps Review has very detailed reviews of a range of Apps, searchable by subject and other tags (R,C,A,$)
A wiki TeachwithyouriPad has an extensive range of Apps categorised in a variety of ways with their page iPad Apps.
Or try this site iPad curriculum, where you can use a search form to search by a range of categories, even by Blooms Taxonomy.
Legend (R=Review, C=Categorised, A=Age Group, $=Cost)