Examine source code of Find Media Files

{
  "manifest_version": 2,
  "name": "Find Media Files",
  "version": "1.1",
  "description": "Find and download media files (audio/video) on the current page.",
  "icons": {
    "64": "logo/64logo.png",
    "128": "logo/128logo.png"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "downloads"
  ],
  "browser_action": {
    "default_title": "Detect Media",
    "default_popup": "popup.html",
    "default_icon": "logo/128logo.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "detector.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "applications": {
    "gecko": {
      "id": "{80ac9e8a-9f39-44a5-aa65-0eda9c541931}",
      "strict_min_version": "79.0"
    }
  }
}