Examine source code of Focusleaf

{
  "manifest_version": 2,
  "name": "Focusleaf",
  "version": "2.3.0",
  "description": "Adds focusing layout and functionality to Overleaf projects",
  "permissions": [
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.overleaf.com/*"
      ],
      "js": [
        "fullscreen.js",
        "js/jquery-ui.js",
        "js/jquery.js"
      ],
      "css": [
        "style.css",
        "jquery-ui.css"
      ]
    }
  ],
  "browser_action": {
    "browser_style": true,
    "default_popup": "popup/settings_page.html",
    "default_icon": {
      "16": "icons/overleaf_16.png",
      "32": "icons/overleaf_32.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{94a935ba-aa1d-4336-9dc9-821e2bb65e68}"
    }
  }
}