This gist shows how to create a GIF screencast using only free OS X tools: QuickTime, ffmpeg, and gifsicle.
To capture the video (filesize: 19MB), using the free "QuickTime Player" application:
Requires grunt-spritesmith which generates a spritesheet from a bunch of images.
This gist passes a custom template for spritesmith to generate the SCSS file.
Gruntfile.js
sprite: {
src: "images/*.png",