Examine source code of AutoLike

{
  "manifest_version": 2,
  "name": "AutoLike",
  "version": "1.0",
  "description": "Automatically likes the video you're watching (according to your own whitelist)",
  "icons": {
    "48": "icons/thumb_up_black.svg"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/watch?v=*"
      ],
      "js": [
        "AutoLike.js"
      ]
    }
  ],
  "options_ui": {
    "page": "pages/options.html"
  },
  "browser_action": {
    "browser_style": true,
    "default_popup": "pages/menu.html",
    "default_icon": {
      "16": "icons/thumb_up_black.svg"
    },
    "theme_icons": [
      {
        "light": "icons/thumb_up_white.svg",
        "dark": "icons/thumb_up_black.svg",
        "size": 16
      }
    ]
  },
  "permissions": [
    "storage",
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "AutoLike@mkrabs.de"
    }
  }
}