Examine source code of RevealMetaInfo

{
  "description": "Returns the info stored in the page's meta tags",
  "manifest_version": 2,
  "name": "RevealMetaInfo",
  "version": "1.2resigned1",
  "homepage_url": "https://github.com/hrmeetsingh/BrowserExtensions/tree/master",
  "icons": {
    "48": "icons/revealMetaInfo-logo.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.com/",
        "*://*.net/*"
      ],
      "js": [
        "revealmeta.js"
      ],
      "css": [
        "revealmeta.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{488e1449-1b26-4a19-bcf0-d4f5c3bd9a89}"
    }
  }
}