ReCap is an interactive site where you can post question and the students video their answers. My students loved this one and ask for it often. While recording, the students have an opportunity to view their response and re-record if they wish.
After the lessons closes (times limits are set) a video is made of the responses. You have the option to edit the video to include 1-6 your students.
The videos are stored in their account, so they can revisit them at the end to see if they mastered their goals.