Works to block the ads and annotations. But now Youtube has a new thing where they force you watch a clicked video after you back out of the page. The said video will continue on your screen as a pop-up window on the bottom right corner. Pretty sneaky and a cheap shot to increase views for the Youtubers. Adblock does nothing for this....I guess it's not an ad so...

Now Youtube has a drop down portion of the screen too. Does nothing for that either. Youtube is unstoppable!

6/16:
The playing video's in the pop-up windows are back. If you view a video that was just click bait and back out of that page the video follows you. This does nothing for it.