Examine source code of ImageTime Travel

{
  "manifest_version": 2,
  "name": "ImageTime Travel",
  "version": "1.0",
  "description": "Compare two images with a smooth before–after slider. Supports PNG, JPG, WebP. Drag & drop or choose files.",
  "icons": {},
  "browser_action": {
    "default_title": "ImageTime Travel",
    "default_popup": "popup.html"
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{cf3b2083-4001-4034-8004-b90ee16b03e0}"
    }
  }
}