Scribl: simple instructional videos

Scribl is a program for creating simple instructional videos. There are plenty of fancy programs out there for making beautiful animations -- this is not one of them. It only aims to be an improvement (both in terms of output quality and creation effort) over the venerable doc-cam + microphone method for creating video lectures.

A sample

Here's a short video created with scribl:

Here's a screenshot of its user interface: