Zaption is a site that allows you to add content to existing videos from Youtube or other sources. I’ve tried it a couple times in class so far and been very pleased with the results. I love the ease of use of Zaption. It does not take long to put together a video with extra text slides and questions and get it out to your students.
Here is a Zaption video about Christmas in Spain I made for students to complete. It is based on two videos.