Vocabulary.com, a great site for enhancing a class’s use of language, has a new mobile app. Called – you guessed it – Vocabulary.com, the software costs $2.99 and has 12,000 words at its disposal along with 125,000 interactive questions about them. The software also has a built-in dictionary, no shortage of vocabulary lists, including those for many popular school books. Each entry goes beyond the meaning and part of speech to include several examples and a graphic way to show its origin. Right now it’s only available for the iPhone and iPad for $2.99 at the iTunes App store but they’re working on an Android version as well. The best part is that you can still have the Web site periodically send students challenge words.