Examine source code of Skipper

{
  "manifest_version": 2,
  "name": "Skipper",
  "version": "1.0",
  "description": "Extension to skip Youtube Ads. Automatic skip functionality as well as manual button or keyboard shortcut (works even before the countdown ends). It only works for skipable ads.",
  "homepage_url": "https://github.com/souzanod/skipper-extension",
  "icons": {
    "24": "icons/skip_next-red-24.png",
    "32": "icons/skip_next-red-32.png",
    "48": "icons/skip_next-red-48.png",
    "96": "icons/skip_next-red-96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "content_scripts/skipper.js"
      ]
    }
  ],
  "options_ui": {
    "page": "options/options.html"
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "skipper@example.com"
    }
  },
  "browser_action": {
    "default_icon": "icons/skip_next-red-24.png",
    "default_title": "Skipper",
    "default_popup": "popup/popup.html"
  }
}