Examine source code of WebSong Collector

{
  "manifest_version": 2,
  "name": "WebSong Collector",
  "version": "0.1.1",
  "description": "Collects metadata of songs you listen to on supported web players and builds a weekly/monthly music map. Exports CSV and shows simple charts.",
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/icon-48.png"
    }
  },
  "icons": {
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "storage",
    "tabs",
    "activeTab",
    "https://open.spotify.com/*",
    "https://*.spotify.com/*",
    "https://music.youtube.com/*",
    "https://www.youtube.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://open.spotify.com/*",
        "*://*.spotify.com/*"
      ],
      "js": [
        "content_spotify.js"
      ],
      "run_at": "document_idle"
    },
    {
      "matches": [
        "*://music.youtube.com/*",
        "*://www.youtube.com/*"
      ],
      "js": [
        "content_youtube.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "websong-collector@example.com",
      "strict_min_version": "68.0",
      "data_collection_permissions": {
        "required": [
          "personallyIdentifyingInfo"
        ],
        "optional": [
          "technicalAndInteraction"
        ]
      }
    }
  }
}