Vocabulary Builder by Magoosh is a free iOS game that helps you build your vocabulary with 1200 expert-selected words. The game has basic, intermediate, and advanced vocabulary sections, and each level you beat unlocks a harder one with more advanced vocabulary. The app uses spaced repetition to help you master the words you don't know, which has been proven to be an effective memorization strategy.

The app also gives you access to all of Magoosh’s general, GRE, SAT, and TOEFL vocab quizzes. You can sign in with a Magoosh account to save your progress to the web and continue your practice online. Vocabulary Builder by Magoosh was created by expert tutors led by Chris Lele, who has been teaching the GRE for over 10 years and is unbeatable in Scrabble.