Screen capture and annotation applications

I found two useful web browser extensions for screen shot capture and annotation.
Both browser extensions are work fine with Mozilla Firefox and Google Chrome.

Following are the links,

Easy Screen Shot

Awesome Screenshot

Fireshot

Aviary

Shutter: a feature rich screenshot tool

Shutter is an advanced screen shot taking tool. You can take screen shot of customised snaps of objects in your desktop. You can select particular area or windows of applications visible in Linux Desktop.

Shutter package is available in Ubuntu software repository.
You install shutter either using command Terminal or Synaptic Manager.

Home page of shutter is http://shutter-project.org/