One of my favorite tools to tell people about is Adobe Spark. It is an online tool that is completely free (with the option to upgrade some features) and can be used on almost any device as long as you have access to the internet. Adobe Spark starts out by giving you a wide range of templates that can be customized so you can create graphics, videos and webpages. With these templates you can easily change the text, graphics or other elements to make powerful multimedia for your courses.