Examine source code of Check this Shop

{
  "manifest_version": 2,
  "name": "Check this Shop",
  "version": "0.6resigned1",
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "description": "Always check with this tool an online shop before ordering anything.",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d504e447-7674-47c8-b013-580c4c15f738}"
    }
  }
}