It allows you to annotate your screen (draw over other apps) and interact with your webcam in real-time (it supports up to 4 webcam configurations).
The app was built from the ground up to reduce cognitive load to a minimum. All tools are spring-loaded and intuitive. Want to draw something? Just swipe. Want to write some text? Double-click. Want to zoom in on something? Scroll up.
It's available for all 3 OS-es, and it's a one-time purchase that you can install on up to 5 computers. Free to try without a credit card.
If you're a content creator or a story teller, I think you'll really like this tool.