Examine source code of SpaceSound

{
  "manifest_version": 2,
  "name": "SpaceSound",
  "version": "1.0",
  "description": "Generates a random ambient space pad and an animated cosmic background when a new tab opens.",
  "icons": {},
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "space-sound.js"
      ],
      "run_at": "document_end"
    }
  ],
  "permissions": [
    "storage",
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{8e8d0ec9-3dc9-4de4-b1ca-79b1daa2cabe}"
    }
  }
}