Examine source code of Balanced Media

{
  "manifest_version": 2,
  "name": "Balanced Media",
  "description": "Help us keep news accountable.",
  "version": "2.4",
  "icons": {
    "16": "icons/inactive.png",
    "48": "icons/inactive.png",
    "128": "icons/inactive.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "addon@balancedmedia.org"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.cnn.com/*",
        "*://www.foxnews.com/*",
        "*://www.npr.org/*",
        "*://www.cnbc.com/*",
        "*://www.buzzfeed.com/*",
        "*://www.washingtonpost.com/*",
        "*://www.msn.com/*",
        "*://nypost.com/*",
        "*://thehill.com/*",
        "*://www.nbcnews.com/*",
        "*://www.bbc.com/*",
        "*://www.usnews.com/*",
        "*://www.nytimes.com/*",
        "*://www.huffpost.com/*",
        "*://www.usatoday.com/*",
        "*://www.reuters.com/*",
        "*://www.politico.com/*",
        "*://news.yahoo.com/*",
        "*://www.latimes.com/*",
        "*://www.breitbart.com/*",
        "*://www.newsweek.com/*",
        "*://www.vox.com/*",
        "*://abcnews.go.com/*",
        "*://www.wsj.com/*",
        "*://www.dailymail.co.uk/*",
        "*://www.theguardian.com/*",
        "*://www.businessinsider.com/*",
        "*://slate.com/*",
        "*://www.telegraph.co.uk/*",
        "*://www.nj.com/*",
        "*://www.independent.co.uk/*",
        "*://www.theatlantic.com/*",
        "*://www.freep.com/*",
        "*://www.boston.com/*",
        "*://www.voanews.com/*",
        "*://www.newsmax.com/*",
        "*://apnews.com/*",
        "*://www.thedailybeast.com/*",
        "*://www.nationalreview.com/*",
        "*://www.theepochtimes.com/*",
        "*://www.csmonitor.com/*",
        "*://www.washingtonexaminer.com/*",
        "*://www.axios.com/*",
        "*://www.motherjones.com/*",
        "*://www.cbsnews.com/*",
        "*://www.seattletimes.com/*",
        "*://freebeacon.com/*",
        "*://www.americanthinker.com/*",
        "*://pjmedia.com/*",
        "*://redstate.com/*",
        "*://thefederalist.com/*",
        "*://theintercept.com/*",
        "*://www.propublica.org/*",
        "*://www.newyorker.com/*",
        "*://www.economist.com/*",
        "*://www.balancedmedia.org/Identity/Account/Register",
        "*://balancedmedia.org/Identity/Account/Register"
      ],
      "js": [
        "libraries/jQuery.min.js",
        "libraries/chart.min.js",
        "contentscripts/embeddedcontent.js"
      ]
    },
    {
      "matches": [
        "https://www.google.com/search?*"
      ],
      "js": [
        "libraries/jQuery.min.js",
        "libraries/chart.min.js",
        "contentscripts/googlesearch.js"
      ]
    },
    {
      "matches": [
        "https://www.reddit.com/*"
      ],
      "js": [
        "libraries/jQuery.min.js",
        "libraries/chart.min.js",
        "contentscripts/reddit.js"
      ]
    },
    {
      "matches": [
        "https://news.google.com/*"
      ],
      "js": [
        "libraries/jQuery.min.js",
        "libraries/chart.min.js",
        "contentscripts/googlenews.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "libraries/jQuery.min.js",
      "background.js"
    ],
    "persistent": true
  },
  "browser_action": {},
  "web_accessible_resources": [
    "embeddedpopup.htm",
    "css/bmbootstrap.css",
    "css/embeddedcontent.css"
  ],
  "permissions": [
    "storage",
    "*://www.balancedmedia.org/api/*"
  ]
}