Examine source code of BigBlueButton buttons

{
  "manifest_version": 2,
  "name": "BigBlueButton buttons",
  "version": "1.3",
  "description": "Adds media-playback controls to BigBlueButton recordings.",
  "content_scripts": [
    {
      "matches": [
        "*://bbb-lb.finki.ukim.mk/*"
      ],
      "js": [
        "bbb_buttons.js"
      ]
    }
  ],
  "browser_action": {
    "default_popup": "popup/popup.html",
    "default_title": "Options"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "skotevski10@gmail.com"
    }
  },
  "permissions": [
    "storage"
  ],
  "icons": {
    "16": "assets/icon_16.png",
    "48": "assets/icon_48.png",
    "96": "assets/icon_96.png",
    "128": "assets/icon_128.png"
  }
}