Here is a demo (click the image below). (created using LICEcap and Zoomit (for annotations))
Here is the link to the Kaltura file that was recorded.
Greenshot can do screen capture and it comes with an image editor that can enrich screenshots with annotation functions. It is a free alternative to snagit. Here is a link to the website of Greenshot. http://getgreenshot.org/.
Screen capture tools allows you to take screenshots, make annotations and share it. Here is a demo of one of such tool that is available for firefox browser.
https://addons.mozilla.org/en-US/firefox/addon/qsnap/ (open ware).
Click the image below to get a glimpse of its use (there is no audio).
I have created the animated GIF file using LICEcap (http://www.cockos.com/licecap/, openware) and increased the speed of GIF file (150%) using the free online services (http://ezgif.com/).