EdPuzzle allows you to take videos (either ones you've created or ones you've found online) and overlay them with narration and quizzes. You can create classes for students to join, so they have the assignments pushed to them with due-dates and instructions. EdPuzzle will even automatically grade the quizzes for you, which should save you a bit of time and hassle. It's a very useful tool for flipping the classroom (or just to make videos more interactive).
This tool is free for teachers and students. Students simply travel to the site, click sign up, then add their first name, username, and password. I would recommend having students include their last initial to help you differentiate those with the same first name. In addition, having them use their ID# for both their username and password might make it easier for you to help them when they forget their login details. Once they create an account, they'll then need the course code to join the class you made for them.
Check out this tutorial playlist from EdPuzzle to learn how to master this resource.