Quizlet is mobile and web-based study application. This application helps students study by flashcards and various games and tests. This allows for students to review topics by many different methods. Quizlets can be shared among teachers, parents, and students. Quizlet tracks what questions you are getting wrong and right over the course of using it so you can see what you need to work on. Teachers can use Quizlet to review material for that lesson but also for the whole unit. Quizlet is a good resource to study units that are broken up into lessons. In my Quizlet, I included a quiz on rhyming words.
Here is a slideshow of some quizzes taken from Quizlet. The first two pictures are of a Geography quiz a user created. The third and fourth pictures are a quiz on French animals.