I signed up to TED ED and used the lesson creator there to make an activity using a video which I chose from Ted Ed by searching using the key Flipped Classroom: Distance learning. The video I liked was called:

Peter Norvig On The 100,000-Student Classroom.

Try the activity here https://ed.ted.com/on/qizu0Txw#watch

It was very easy to create the activity, which, as suggested by Norvig in his talk, should not only consist of multiple-choice questions but also involve open questions which are less automatic and require reflection and - dare I say it - critical thinking.

I found it very useful that the teacher can collect the answers of all who respond and therefore know which kinds of formative feedback to offer.