Examine source code of FreeShopper

{
  "manifest_version": 2,
  "name": "FreeShopper",
  "description": "Welcome to FreeShopper, where you’ll find a collection of the best deals on some of your favorite products and services!",
  "version": "1.2resigned1",
  "browser_action": {
    "default_icon": "icon.png",
    "default_title": "FreeShopper"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "jquery-3.0.0.js",
        "handler.js",
        "relevancy.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "permissions": [
    "notifications",
    "tabs",
    "activeTab",
    "webNavigation",
    "storage",
    "*://*/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "web_accessible_resources": [
    "icon.png",
    "rewards.json"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{8f33a310-41a6-4a27-a4e3-70a0c8fb7051}"
    }
  }
}