Examine source code of Music Compressor

{
  "manifest_version": 2,
  "name": "Music Compressor",
  "version": "1.0",
  "description": "Compress your music files easily!",
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "permissions": [
    "downloads",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{b9ffbde8-f3b4-4573-a3a4-5b4da92af03d}"
    }
  }
}