Examine source code of Hidebar

{
  "manifest_version": 2,
  "name": "Hidebar",
  "version": "1.0.1.2resigned1",
  "description": "Hides sidebars on youtube and other sites",
  "icons": {
    "48": "clock.svg"
  },
  "permissions": [
    "storage",
    "tabs"
  ],
  "browser_action": {
    "default_icon": "clock.svg",
    "default_title": "Hidebar",
    "default_popup": "hidebarPopup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/*",
        "*://*.stackexchange.com/*",
        "*://stackoverflow.com/*",
        "*://www.quora.com/*",
        "*://www.buzzfeed.com/*"
      ],
      "js": [
        "hidebar.js"
      ],
      "run_at": "document_end"
    }
  ],
  "applications": {
    "gecko": {
      "id": "{0f3f16a9-745e-4c3b-8e3a-050038c53cec}"
    }
  }
}