Examine source code of Better YouTube Previews

{
  "manifest_version": 2,
  "name": "Better YouTube Previews",
  "version": "2.36.0.1",
  "description": "Make YouTube video previews play on long click instead of hover.",
  "permissions": [
    "activeTab",
    "storage",
    "*://www.youtube.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "all_frames": true,
      "run_at": "document_start"
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "images/icon-16.png",
      "32": "images/icon-32.png",
      "48": "images/icon-48.png",
      "128": "images/icon-128.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "icons": {
    "16": "images/icon-16.png",
    "32": "images/icon-32.png",
    "48": "images/icon-48.png",
    "64": "images/icon-64.png",
    "128": "images/icon-128.png"
  },
  "web_accessible_resources": [
    "images/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "hover@davidschiller.net"
    }
  }
}