Quizlet
Quizlet lets you create custom study sets or information sets that can be shared. It's useful for test prepping, flashcards, and more.
Kahoot!
Kahoot! is a game-based tool that incorporates learning and playing together that is flexible, simple, diverse, and engaging to use for things like quizzes, surveys, discussions, lessons, or studying.
Nearpod
Nearpod is a software with many features such as quizzes, polls, drawings, open-ended questions, fill-in-the-blanks, 3D objects and more that make teaching and learning more interactive and engaging.