Examine source code of Image Metadata Viewer

{
  "manifest_version": 2,
  "name": "Image Metadata Viewer",
  "version": "1.0",
  "description": "View EXIF metadata from selected images.",
  "browser_action": {
    "default_title": "Image Metadata Viewer",
    "default_popup": "popup.html",
    "default_icon": "icons/icon.png"
  },
  "icons": {
    "48": "icons/icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{06e0860e-007c-4945-8025-951cf140ac16}"
    }
  }
}