Examine source code of Ninja Hacker Cat

{
  "manifest_version": 2,
  "name": "Ninja-Hacker-Cat",
  "description": "Cute Script Kitty makes web security checks for you!",
  "version": "1.7",
  "browser_action": {
    "default_icon": "/images/cat-default-grey.png",
    "default_title": "Miau!"
  },
  "background": {
    "scripts": [
      "/scripts/background.js"
    ]
  },
  "permissions": [
    "notifications",
    "webRequest",
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{eaf361f5-2194-48f8-b15b-98ea9b9382ca}"
    }
  }
}