SAT/GRE Vocab Preview This is a free flashcard app with 50 common words used in the SAT and GRE. You can mark cards to show you've learned them already and you can view them in order or randomly.

Phonetics flashcards study aid This is a really cool and generally useful study tool for learning Phonetics. You can see where in the mouth the sound is made and hear the pronunciation. The only downside to this app is that it is missing the vowels!

Sociology Study Guide This app is US$9.99 and is a very complete and well referenced guide to sociology. Includes chapters on the foundations of sociology, social life, social psychology, organizational behavior, social inequality, social institutions, social change, and famous sociologists. You can add bookmarks, search the content, access offline, and it lets you mark up and annotate the content. Recommend.

Key Transposer This effective, easy to use and simple program transposes keys in music. It supports 15 keys. You can also use it as a learning tool for chords and key relationships. Recommend.

AP Art History Exam Prep This app costs US$3.99 and presents 130 questions realistic to the AP Art History Exam - and full explanation of all of their answers. International range of art history covered in the topics and a few different learning tools.