Examine source code of No Sardard

{
  "manifest_version": 2,
  "name": "No Sardard",
  "version": "3.0",
  "description": "Reduce eye strain by applying a blue light filter to web pages. Made with love for my Manisha's gorgeous eyes. Now with custom scheduling, persistent settings, and enhanced full-screen support.",
  "permissions": [
    "storage",
    "tabs",
    "activeTab"
  ],
  "browser_action": {
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "applications": {
    "gecko": {
      "id": "blue-light-filter@example.com"
    }
  }
}