Many valuable resources for Educators!
Check it out! http://edpuzzle.com/#
I also added a sample video below from their website. It doesn't have sound so you can record over it. It's an idea on how to teach integers.
The website is http://www.chartle.net/.
Below is a how-to that is provided on their site as well.
The Teaching Channel
Surfnetkids- Surfing the Net with Kids
There is a video below that explains how to make a crossword puzzle using this software.
Create A Graph
I also included a short how-to video below on how to record in this application.