John P. Bloch

Create child themes from any non-child theme with the click of a button.
This plugin is multisite compatible; if used on a multisite network, controls for creating child themes will be in the network admin instead of the regular site admin. Pick the parent theme from the dropdown and name name your new child theme. You can also change the author name and select files you want to copy from the parent to the new theme.
Click the button and you’re all set!

Child Themify

Create child themes with the click of a button.

Gecka

PHP 5 required. Please be sure to check your PHP version before marking the plugin as broken.
Submenu enhances the WordPress 3.x navigation system. When you have a website based on WordPress with a lot of pages, but you need a custom menu, it can be tedious to have to add a menu entry for each page created. Submenu just does it automatically.
Submenu also allows you to put menus or portion of menus anywhere in your site: sidebar, templates or page contents.
Languages available: english, french
Contribute: <a href="https://github.com/Gecka-Apps/Wordpress_Gecka_Submenu" rel="nofollow ugc">This plugin is on GitHub</a> !
<a href="http://gecka-apps.com/wordpress-plugins/gecka-submenu-pro/" title="Discover the pro version" rel="nofollow ugc">Discover the pro version</a> by checking out the <a href="http://www.youtube.com/watch?v=DHjMfD-k2Mo" rel="nofollow ugc">Gecka Submenu Pro video</a>:
<iframe loading="lazy" class="youtube-player" width="750" height="422" src="https://www.youtube.com/embed/DHjMfD-k2Mo?version=3&rel=1&showsearch=0&showinfo=1&iv_load_policy=1&fs=1&hl=en-US&autohide=2&wmode=transparent" allowfullscreen="true" style="border:0;" sandbox="allow-scripts allow-same-origin allow-popups allow-presentation allow-popups-to-escape-sandbox"></iframe>

Gecka Submenu

Works fine for me

Submenu autopopulates any nav menu page item with its children and allows to put menus, or portion of menus, anywhere in your site.

Child Themify vs Gecka Submenu