Examine source code of Tracking Time Button

{
  "name": "__MSG_appTitle__",
  "short_name": "Tracking Button",
  "manifest_version": 2,
  "version": "2.19",
  "author": "Tracking Time LLC",
  "default_locale": "en",
  "description": "__MSG_appDesc__",
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "icons": {
    "128": "img/favicon.png"
  },
  "background": {
    "persistent": true,
    "scripts": [
      "js/lib/jquery-3.3.1.min.js",
      "js/lib/moment-with-locales.min.js",
      "js/extension-helpers.js",
      "js/device_api.js",
      "js/model.js",
      "js/translate.js",
      "environment.js",
      "settings.js",
      "js/abstract/custom-jquery-ajax-localstorage-cache.js",
      "js/abstract/crud.js",
      "js/abstract/json_crud.js",
      "js/abstract/local_crud.js",
      "js/abstract/time_manager.js",
      "js/abstract/amazon_websocket.js",
      "js/abstract/currentUser.js",
      "js/domains.js",
      "js/options.js",
      "js/notifications.js",
      "js/background.js"
    ]
  },
  "permissions": [
    "*://*.trackingtime.co/*",
    "*://*.trackingtime.io/*",
    "tabs",
    "notifications",
    "cookies"
  ],
  "web_accessible_resources": [
    "options.html"
  ],
  "optional_permissions": [
    "*://*/"
  ],
  "browser_action": {
    "default_title": "TrackingTime",
    "default_icon": {
      "32": "img/iconos/32x32_grey.png"
    },
    "default_popup": "index.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{2a32154a-d803-44b0-a19e-63dc32f10faa}"
    }
  }
}