Browser JS Error Badge is a simple tool that helps you keep track of JavaScript errors on your website by displaying a badge in the browser.
Add extenstion to your browser
Google Chrome - https://chrome.google.com/webstore/detail/browser-js-error-badge/alnmeadckaeolemiacdddeooegfmaigl
Firefox - In the works
Browser JS Error Badge is released under the MIT License. See LICENSE for details.