Alcamy - Free, open self-learning platform. Learn & teach anything.
Scrimba - Interactive coding screencasts created in an instant
Airschool - Airschool is a live-streaming educational platform with engagement and monetization tools to help anyone start teaching online. It can be finance, business, wellness, meditation, branding, marketing; in short, anything you want!
Vidrio - Holographic screencasting app for Mac. Free for COVID-19
Stacks - A bookshelf for your online courses
GoRails - Ruby on Rails screencasts for Web Developers