Agreement errors are some of the most common grammar errors among both English language learners and native speakers. Moreover, correct subject-verb agreement is the key to successful academic and professional writing. This app helps the user to quickly identify agreement errors. Random sentences are generated, and the user selects whether the agreement is correct or not. After a series of sentences, the user has a chance to review their answers as well as the parts of speech in each sentence to help them identify the subject and verb correctly.