Examine source code of Quote the Day

{
  "manifest_version": 2,
  "name": "Quote of the Day",
  "version": "1.0",
  "description": "Get an inspiring quote every time you open the popup.",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{447fdb2e-fac5-4fda-8873-ca13bb770a91}"
    }
  }
}