Examine source code of BlockSite

{
  "manifest_version": 2,
  "background": {
    "page": "background.html"
  },
  "web_accessible_resources": [
    "blocked.html",
    "welcome.html",
    "img/notify-avatar-blue.png",
    "img/notify-avatar-red.png"
  ],
  "default_locale": "en",
  "description": "__MSG_appDesc__",
  "name": "Block Site",
  "short_name": "__MSG_appShortName__",
  "permissions": [
    "tabs",
    "webNavigation",
    "<all_urls>",
    "cookies",
    "management",
    "notifications",
    "contextMenus",
    "webRequest",
    "webRequestBlocking",
    "unlimitedStorage",
    "storage"
  ],
  "version": "4.0.8.3resigned1",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_end",
      "js": [
        "content.js"
      ]
    }
  ],
  "icons": {
    "16": "img/icon16.png",
    "19": "img/icon19.png",
    "32": "img/icon32.png",
    "48": "img/icon48.png",
    "128": "img/icon128.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "img/icon16.png",
      "32": "img/icon32.png"
    },
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{dd3d7613-0246-469d-bc65-2a3cc1668adc}"
    }
  }
}