Revert Site lets you get the old Facebook site design back with the blue bar at the top.
Revert Site lets you get the old Facebook design / layout back. It makes Facebook think you are using an old out of date browser, so it shows you the old design instead of the new one, and also prevents Facebook from switching you back to the new design (until they completely remove the old design, which may be a few months time or longer)
Revert Site is very quick to install, and very easy to use, it just has a single option, that is turned on by default, so you can just install it and not have to configure anything. However if you wish to temporarily disable Revert Site, you can easily do so by clicking the extension icon, in the browser's extensions toolbar, then un-ticking the "Switch back to the old Facebook design" checkbox. To turn it back on, just re-tick the checkbox.
If you can't find the Revert Site (R) button in your extension's toolbar, it may be hidden behind the "Jigsaw puzzle piece" button, so click that and see if its behind there.
**** PLEASE NOTE ****
Revert Site cannot revert the newsfeed (facebook homepage as facebook redirects that page to the mobile version of the Newsfeed ( m.facebook.com ). Messaging also seems to be broken. However nearly all other pages on the site should revert ok back to the old facebook design (such as Pages, Personal profiles, Groups etc) If you are on the mobile version of one of these pages, a and you have the revert option turned on, reloading the page should get the revert function to kick in.
Please also note If you have any problems with chat / messages/ video and voice chats on the Facebook site, with this extension installed, as a workaround you could load Facebook's auxiliary messaging website, messenger.com in a new tab to do your Facebook video and voice calls and messaging / chats.
If you find there are any parts of the site that won't work with the Revert option turned on, switch it off while you carry out your tasks, then turn it back on when you have finished to go back to the old site again.
You can stay up to date with the Revert Site news by liking and following the Revert Site Fan Page at https://fb.com/revertsite
BTW Please check out my other extension which works on the new & old Facebook design: FB Purity : https://is.gd/fbpchrome
It lets you Clean up and Customize Facebook, hides all the ads & makes Facebook less annoying & more fun to use, having FB Purity installed, also makes Revert Site work better on certain pages of the site.