Remembers the sroll position of the page, great for reading really long pages.
Imagine you're reading a very long article. You don't have time to finish it now, but if you leave the page and come back later you'll lose the position you're up to.
That's where this spectacularly useful extension comes to your rescue. Just click the icon and BAM, your position on the page will be remembered (on any computer you have Chrome syncing).