Edpuzzle is an easy-to-use platform where you can make any video your lesson. One click and you can find video-lessons created by other teachers with formative assessment included! Another click and you can adjust that video by embedding your own questions or audio during the video. Final click, you assign it to your students and get beautiful hassle-free analytics: who watched the video, who didn't understand the lesson, and who did a good job. Students can re-watch the video as many times as they need, at their own pace. You can comfortably check their progress from your account.
The above comes directly from their website!
Edpuzzle comes highly recommended by Mark Lyons - an elementary tech instructor in the Canon City, CO school district.
Thanks for the reminder, Mark!