Bubba Brain is a simple site packed with review games for students preparing for the SAT and AP exams. Bubba Brain also has some games for elementary and middle school subjects. The games all use the same format of giving a definition and asking students to find the word or term that it matches. Once a correct match is made, a new definition appears on the "back" of the answer to the previous definition.
Applications for Education
Bubba Brain isn't the fanciest game site you'll ever see but it does offer enough review games to keep students using it. It's probably not a site that you'll have students use in class, but it is a site that you might recommend to them to use at home to prepare for a standardized test.
Here are some related items that may be of interest to you:
Word Ahead Vocabulary Videos
WeboWord - Vocabulary Visualized
Vocab Sushi - Fresh, Bitesize Vocabulary Practice