Examine source code of DownloadPro Plus

{
  "manifest_version": 2,
  "name": "DownloadPro",
  "version": "1.0",
  "description": "Automatically resume interrupted downloads, even after browser restarts",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [
    "downloads",
    "downloads.open",
    "storage",
    "notifications",
    "tabs"
  ],
  "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": "{1bfb3205-38cb-4955-91b5-1a78b89ff297}"
    }
  }
}