Examine source code of Startpage Enhancer Pro

{
  "manifest_version": 2,
  "name": "Startpage-enhancer",
  "version": "0.3.6",
  "description": "Make Startpage more awesome. Currently it supports adding the search-queue to the title of the tab, add Maps-Links and Favicons.",
  "icons": {
    "48": "icons/icon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.startpage.com/*"
      ],
      "js": [
        "enhance.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f63993d1-6241-4257-8f0a-c3e2ea4cddbf}"
    }
  }
}