Examine source code of Twitch Browser Notification

{
  "manifest_version": 2,
  "name": "Twitch Live Notification in Browser",
  "author": "Medivha",
  "version": "1.1.7",
  "description": "Get instant browser notifications when your followed Twitch streamers go live. Automatically syncs your follow list, supports in-page and system notifications, and keeps you updated in real-time.",
  "permissions": [
    "storage",
    "tabs",
    "notifications",
    "alarms",
    "identity",
    "https://id.twitch.tv/*",
    "https://api.twitch.tv/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_title": "Twitch Browser Notification",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png"
    }
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "contentScript.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "web_accessible_resources": [
    "sounds/*.mp3"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "twitch-live-notifier@test",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}