When you’re reading an article on Wikipedia it can be annoying when you feel the need to continuously click the links that are referenced just to see what that word means or how it is relevant to what you’re reading. For example, what if you wanted to find out the name of the actor that plays Sheldon Cooper in The Big Bang Theory sitcom. The first thing I’d probably do is go to the Wikipedia page for the show, and look for where the character is mentioned. I’d then follow the link to find the information I was looking for.
As you can see in the screenshot above the WikiPreview extension for Chrome will show you the first couple lines from the associated Wikipedia page just by hovering over the link. In doing that I can find out that the role is played by Jim Parsons without even clicking on the link. Now imagine how useful this would be if you were reading something unfamiliar where you’d constantly be clicking on links just to follow along. This is perfect for those situations.
The only thing I don’t like is that this extension only works for links that are on a Wikipedia page, and won’t popup for links to Wikipedia pages on third-party sites. Maybe the developer will add something along those lines in a future update.