Examine source code of Just Breathe (Dark)

{
  "manifest_version": 2,
  "name": "Just Breathe",
  "version": "1.0",
  "description": "A free and simple guided breathing extension for reducing stress and enhancing mental wellness.",
  "permissions": [],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "128": "images/just-logo.png"
    }
  },
  "icons": {
    "128": "images/just-logo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{cc681388-95b0-45ed-9b88-48a2b876ab62}"
    }
  }
}