Easy Maintenance Mode is customizer base plugin in which user just need to assign page to show as maintenance mode.
If you find this plugin useful, please leave a good rating and consider checking out my other plugins:
Easy Author Avatar Image – Set your choice of avatar image.
Enhanced Comment Validation – Setup a comment validation for comment form.
Landing page for WC Archive Pages – allow you to add Rich text for your WooCommerce archive( Shop, Product Category, Product Tags ) pages.