A wonderful website for creating screencasts is Screencast-O-Matic.com. You or your students can record up to 15 minutes of video with the free version. Then download the completed video directly to your computer or post to YouTube without even creating an account.Creating a free account allows you to store your videos on Screencast-O-Matic and use a link to share your creation.
The paid version of the program is ONLY $15.00 a year. With the upgrade you can create longer videos and edit using overlays, cutting tools, audio inserts, and more.
This tool is perfect for teachers that want to flip their classroom or just want to create and share how-to tutorials for their students.
Here's a short video on YouTube that shows how to use the site - https://youtu.be/xiTymQcKGeE.