Examine source code of Daily Website Opener

{
  "manifest_version": 2,
  "name": "Daily Website Opener",
  "version": "1.0.1",
  "description": "Open a specific website when Firefox is launched or brought to foreground.",
  "icons": {
    "48": "icon-48.png",
    "128": "icon-128.png"
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "daily-website-opener@lich"
    }
  }
}