Examine source code of Jump Youtube

{
  "manifest_version": 2,
  "name": "Jump",
  "version": "1.0",
  "description": "Automatically skip advertising on Youtube",
  "icons": {
    "48": "icons/jump.png"
  },
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "jump.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": "icons/jump.png",
    "default_title": "Jump"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "jumpytube@example.it"
    }
  }
}