This is a dead-simple Chrome extension that allows you to quickly peek at the width and height of your viewport. Useful for testing breakpoints while developing a site, or just for satisfying your general curiosity vis-a-vis the width and height of your browser viewport.
Clone the repo and follow these instructions for loading an 'unpacked' extension: https://developer.chrome.com/extensions/getstarted#unpacked
I'm still deciding whether I want to deal with the Chrome webstore, or deal with hosting my own .crx file to distribute the extension. Stay tuned...