Peter Westwood

This plugin allows you to run loops within your WordPress templates where you query for children of the current page.
The plugin extra arguments to the list of arguments supported by query_posts().
The query argument <code>child_of</code> is used to add a WHERE to the database query to limit the pages returned to those with a post_page equal to the argument provided.
The query argument <code>child_limit</code> is used to limit the number of pages returned.
The query argument <code>child_offset</code> is used to offset the limiting to allow for pagination if required.

PJW Query Child Of

This plugin allows you to run loops within your WordPress templates where you query for children of the current page.

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.

PJW Query Child Of vs Child Themify