With the ImTranslator you hit a flash foreign words directly to the browser.
So not understood include websites of the past.
4: Easy YouTube Video Downloader
"Easy YouTube Video Downloader allows you to drag clips to YouTube with just one click on your hard drive and play. In this case, the name and "just" an operating maxim.
With the add-on allows you to block malicious scripts. This not only high security, but can - correctly configured - remove unwanted elements from pages.
2: Video DownloadHelper
This video on YouTube and Co. can be easily downloaded and available in various resolutions.
1: Adblock Plus
The extension removes the annoying pop-ups and advertisements from a website. It makes surfing the web much more enjoyable.