Examine source code of Differo

{
  "description": "Find alternative coverage for news",
  "manifest_version": 2,
  "name": "Differo",
  "version": "0.3.3resigned1",
  "homepage_url": "https://github.com/grigoryk/differo",
  "icons": {
    "48": "icons/ext.png"
  },
  "applications": {
    "gecko": {
      "id": "differo@grigory.ca",
      "strict_min_version": "45.0"
    }
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.rt.com/*",
        "*://*.bbc.com/*",
        "*://*.foxnews.com/*",
        "*://*.cbc.ca/*",
        "*://*.csmonitor.com/*",
        "*://*.aljazeera.com/*"
      ],
      "js": [
        "vendor/jquery-3.0.0.min.js",
        "vendor/underscore-min.js",
        "vendor/react.js",
        "vendor/react-dom.js",
        "js/storage.js",
        "js/popularWords.js",
        "js/supportedSites.js",
        "js/differo.js"
      ],
      "css": [
        "css/sidebar.css"
      ]
    }
  ]
}