Examine source code of DownloadPro

{
  "manifest_version": 2,
  "name": "DownloadPro",
  "version": "1.0",
  "description": "Advanced Download Scheduler: Schedule downloads for specific times or when network usage is low",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "downloads",
    "downloads.open",
    "storage",
    "alarms",
    "notifications",
    "webRequest",
    "<all_urls>"
  ],
  "browser_action": {
    "default_icon": "icons/icon-48.png",
    "default_title": "DownloadPro",
    "default_popup": "popup/popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f3d26e1c-a834-4c65-9db9-c6aa46bc71e4}"
    }
  }
}