Examine source code of SEO Snapshot

{
  "manifest_version": 2,
  "name": "SEO Snapshot",
  "version": "1.0",
  "description": "Provides a snapshot of SEO-related attributes for the current page.",
  "icons": {
    "48": "icons/seo-snapshot-icon-48.png"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icons/seo-snapshot-icon-48.png",
    "default_popup": "popup.html",
    "default_title": "SEO Snapshot"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{30d0ecae-c0be-4fad-8e46-701d26c5a505}"
    }
  }
}