Examine source code of Image Series Collector

{
  "manifest_version": 2,
  "name": "Image Series Collector",
  "version": "1.0",
  "description": "Detects images with sequential filenames and suggests batch download.",
  "permissions": [
    "downloads",
    "activeTab"
  ],
  "icons": {
    "48": "icons/icon48.png"
  },
  "browser_action": {
    "default_title": "Image Series Collector",
    "default_icon": "icons/icon48.png",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{b7eb41bf-e1ca-4234-b58f-69935dac5c7d}"
    }
  }
}