Examine source code of DOM-XPath

{
  "manifest_version": 2,
  "name": "DOM-XPath",
  "version": "1.0.4",
  "description": "Find elements in the page by building an XPath expression.",
  "browser_action": {
    "default_popup": "popup.html"
  },
  "permissions": [
    "activeTab"
  ],
  "icons": {
    "32": "dxp-32.png",
    "64": "dxp-64.png",
    "128": "dxp-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{43ce1027-abf8-4ae4-a6a6-dffbf94c7d7a}"
    }
  }
}