Examine source code of Lofi-Box

{
  "manifest_version": 2,
  "name": "Lofi-Box",
  "version": "2.0.0",
  "description": "Relaxing lo-fi tunes directly within your web browser.",
  "icons": {
    "1000": "static/icon.png"
  },
  "browser_action": {
    "default_title": "Lofi-Box",
    "default_popup": "html/popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b1bb902c-62e9-4ec0-851a-ce84760665b8}"
    }
  }
}