Just go to where the video is located.
Wait a second or two.
Click on the 'Icon' for 'video download helper' and it will auto detect the video's on the page your viewing.
The information about the video's on the page your viewing is then displayed. Click on 'Download' for the video you desire and it starts. The progress of the download can be displayed, such as 'Bit Rate' and percentage left. You can then go onto another video and select it. Multiple downloads are allowed. I usually limit it to no more than four, and try not to wander off to far from the video's webpage, just in case my connection isn't at its peak.
You can also pre-set the options for the download.
I use HD, 1080 and MP4. If the video is not offered in 1080, 720 is used.
Bottom line. Easy to setup and use.