All of these apps relate to either iPhone, iPad or iPod touch. All of these apps are free and recommended for student learning.

General learning/organisation/presentation:
Audioboo.png Audioboo is great for podcasting up to 5 minutes (no editing). Photo and location map can be added.
Dictionary.png is a useful app with both thesaurus and dictionary.
Evernote.png Evernote. Sync to mobile devices and/or PC and Mac. Take notes, pictures, audio, URL clippings into one notebook.
Evernote_peek.png Evernote Peek is for iPad2 only. Here you can revise for tests and peek under the iPad cover to check the answers.
My_homework.png MyHomework is an app where students can list all of their tasks by subject. No more excuses for forgetting homework!