Examine source code of Focused StackExchange

{
  "manifest_version": 2,
  "name": "Focused StackExchange",
  "version": "1.0.3",
  "author": "Eric Xing",
  "description": "Hides clutter from StackOverflow/StackExchange",
  "icons": {
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "browser_action": {
    "default_icon": "icons/icon-128.png",
    "default_title": "Focused StackExchange"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.stackoverflow.com/*",
        "*://*.stackexchange.com/*",
        "*://*.askubuntu.com/*",
        "*://*.mathoverflow.net/*",
        "*://*.serverfault.com/*",
        "*://*.stackapps.com/*",
        "*://*.superuser.com/*"
      ],
      "run_at": "document_start",
      "js": [
        "focusedSE.js"
      ],
      "css": [
        "style1.css"
      ]
    }
  ]
}