This is the first screencasting app I explored on the iPad, and I find it very simple to use. The $2.99 price tag makes this a great deal! If you are familiar with basic iPad functions, I think you'll feel the same way.
There is now an Android version of the app (same price - available HERE
If you use a Mac, your Explain Everything files can easily be viewed on your computer with this free app
(available in the App Store)