Grids & Rulers Extension Grids & Ruler is an extension that add a new panel to Chrome developer tools. That panel let you create and manage overlays on pages that provide you visual hints to develop you web app layouts. Read more
Source Manifest.json {"update_url": "https://clients2.google.com/service/update2/crx", "manifest_version": 2, "name": "__MSG_extensionName__", "description": "__MSG_extensionDescription__", "version": "2.0", "default_locale": "en", "icons": { "16": "img/icon.16.png", "32": "img/icon.32.png", "48": "img/icon.48.png", "64": "img/icon.64.png", "96": "img/icon.96.png", "128": "img/icon.128.png" }, "permissions": [ "storage", "unlimitedStorage" ], "background": { "scripts": [ "lib/chrome-polyfill.js", "background.js" ] }, "content_scripts": [{ "matches": [""], "js": [ "lib/chrome-polyfill.js", "content/js/grids.js", "content/js/rulers.js", "content/main.js" ], "css": [ "content/css/grids.css", "content/css/rulers.css" ] }], "devtools_page": "devtools.html"} Read more