Why not send your lectures home for homework and spend class-time with the application? That's right, we do direct instruction independently using the tools below and spend class coaching and assisting the application. It allows you to attempt more complex projects where hands-on assistance would be required. Students struggling with language or missing class can use the take-home lecture content as scaffolding. Lastly, the content you build can continue to grow, making your prep easier and building a pretty cool collection.
The web-based screen recorder has frustrated teachers in the past. Stick with the downloaded version. You'll need to login and download the client. Once you want to publish something, you'll need to link it back to your Screencast-O-Matic account. It'll pop open a browser and let you login with Google again. Easy. These links can then be shared with your students. I recommend building a GitBook or some other page to index all your recorded video.