Quizizz is a competitive quizzing tool that can be used for formative testing.
With Quizizz, you can easily create online formative tests that are very engaging and provide you with useful learning analytics. A quiz from scratch is easy to make, but you can also duplicate existing quizzes, or copy questions from existing quizzes. In class, you give your students a code (similar to Kahoot), and they can join the quiz. After the quiz has ended, you get to see an overview which shows which questions went well and which didn't. You can also see how each individual student did in a clear overview.
Click here to see/play an example of a Quizizz.