flashblock
FlashVideoReplacer
Replace embedded flash videos and display them with a different plugin or standalone player, download or automatically redirect to WebM player when available.
License:
GPL-3 
Installer URL:
https://addons.mozilla.org/firefox/downloads/latest/161869/addon-161869-latest.xpi?src=dp-btn-primary
Source URL:
https://github.com/webgapps/flvideoreplacer
Project URL:
http://webgapps.org/add-ons/flashvideoreplacer/
