From Word Power:
Vocabulary Builder is a program that sits in your system tray completely out of the way and helps you learn new vocabulary quickly and effectively. Every day, at a time you specify, the program launches itself and presents you with a new random word and definition to learn. Also included is a flash card mode where the definition is hidden until you click on the screen. This feature works well for studying for standardized test. In addition, you can search the entire database to look up any word you want so you are actually getting a desktop dictionary as well. The word list has over 4,800 words and includes the most commonly tested words for the SAT, GRE, LSAT, and MCAT.