Marq is a Chrome extension that allows you to right-click any word on a webpage and place a bookmark at that location, drawing a horizontal line across the page.
When you visit the same page in the future, you'll see the same line show up and the page will scroll to that location.
Bookmarks are stored in a folder called Marq, which is in the Bookmarks Bar folder. It can be moved anywhere, but deleting it will result in it being recreated.
To install, visit the webstore. If you would like to install it locally and tinker, follow these instructions.