I tried Explain Everything some time back. I generally enjoyed the app, but was critical that it only displayed a partial screeen on Chrome OS. Yesterday, I tried it again and noticed that Explain Everything was now full screen.
When my trial is up I will strongly consider purchasing this app. In the video below I was thinking less about screencasting and more about using Explain Everything as a whiteboard demonstrating an upcoming activity to students.
The activity I choose was Sink the 10 Frame, a game / activity that supports early math development. One nice thing about Explain Everything is it supports gesture that is used so often in teaching.