Today's free stuff comes from Dark Reader and it's an extension that works on both Chrome and Firefox. It's called Dark Reader. I've been using it on Firefox for a while now and it's an excellent extension.
At the click of the top bar icon, this extension inverts brightness of web pages reduces the strain on your eyes while browsing the web. In dark mode it's good for night browsing. It's also highly customizable. Go on ahead and install it on your Chrome or Firefox browser for free and check it out. (Safari has the extension, but is $4.99 to download. Not free.)