Press PrintScreen and can't grab the entire webpage because it is longer than the browser window? You need FireShot!
Unlike other extensions, this plugin provides a set of editing and annotation tools, which let users quickly modify captures and insert text and graphical annotations. Such functionality will be especially useful for web designers, testers and content reviewers.
Screenshots can be saved to disk (PNG, GIF, JPEG, BMP), printed (NEW), copied to clipboard, e-mailed and sent to external editor for further processing.
A free image hosting web-server is also provided.
To add firefox visit:https://addons.mozilla.org/en-US/firefox/addon/5648/
For more info visit the official website producer: http://screenshot-program.com/fireshot/