Triventy is an online tool that allows you to create easy to use formative assessments or reviews that you can do with students in class. The biggest difference that Triventy has from other online review tools is that it allows for collaborative creation of games and reviews. This can be great if you work in a team setting (middle school I'm thinking of you!) or if your department wants to work together on something that you all can use. You could also have groups of students create reviews and work together that way.
A few other features I like about this tool is the ability to add hints to the questions so students who are struggling can get some extra help without being obvious, and the ability to add extra facts or feedback after each question. You can also adjust some of the quiz settings itself so that it won't display student names with results as you are playing.
One of the biggest downsides of this tool for me is that right now it does not keep the results after the game is done, so you have to take a screenshot of the final results to keep those. It's not a huge inconvenience, but I like having the results in a spreadsheet so I can look back later and see what topics I might need to revisit or where certain students had issues. I hope this is a feature that we will see in the future, but for now that's the only real downside for me with this tool.
For more information on how to use Triventy and how to create quizzes, check out the video below from FreeTech4Teachers.com . FreeTech4Teachers is a great blog and a great resource for all kinds of free tech tools!