Examine source code of SpotJump

{
  "manifest_version": 2,
  "name": "SpotJump",
  "version": "1.0.0",
  "description": "Jump from YouTube to Spotify instantly",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    },
    "default_title": "Jump to Spotify"
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ]
    },
    {
      "matches": [
        "*://open.spotify.com/*"
      ],
      "js": [
        "spotify_content.js"
      ],
      "css": [
        "styles.css"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "spotjump@harshdeepsingh.in",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}