Flipgrid allows for questions to be written by the instructor. Below is a question that I wrote. I was able to create a video board of responses. The board can be public or private which is password protected.
Students or teachers can respond in a simple video format. First they must provide a snap shot of themselves. After that, they allow the program to use their camera and record their response to the question.
The final piece is the moderation. The instructor can watch the videos prior to them being available for others to view. Once approved, members who have the password to the video response board can watch other members responses. They may then "like" the video. The responses can be sent out as a link, embedded, tweeted or sent to Facebook.
All of the videos can be placed separately or as a continuous slide show.