Examine source code of Quickify: Spotify Web Player

{
  "manifest_version": 2,
  "name": "Quickify: Spotify Web Player Shortcuts",
  "version": "1.3.8",
  "description": "Provides a quick way of interacting with the Spotify Web Player without losing context of your current webpage. (Fork with Cover art)",
  "icons": {
    "19": "icons/quickify_19.png",
    "38": "icons/quickify_38.png",
    "48": "icons/quickify_48.png",
    "128": "icons/quickify_128.png"
  },
  "browser_action": {
    "default_icon": {
      "19": "icons/quickify_19.png",
      "38": "icons/quickify_38.png"
    },
    "default_title": "Quickify",
    "default_popup": "popup.html"
  },
  "author": "Diego Accame",
  "background": {
    "persistent": false,
    "scripts": [
      "messages.js",
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://open.spotify.com/*"
      ],
      "js": [
        "messages.js",
        "quickify_content.js"
      ]
    }
  ],
  "options_ui": {
    "page": "options.html"
  },
  "permissions": [
    "tabs",
    "https://open.spotify.com/*",
    "storage"
  ]
}