Sergey Biryukov

Automatically includes a parent theme RTL stylesheet for a child theme if it doesn’t have its own <code>rtl.css</code> file.
Thanks to <a href="http://www.wp-tricks.co.il/" rel="nofollow ugc">Rami</a> for the idea.

Include Parent Theme RTL CSS

Allows to include a parent theme RTL stylesheet for a child theme.

KamataRyo

<a href="https://github.com/KamataRyo/inherit-theme-mods" rel="nofollow ugc">This plugin is hosted on github.</a>
Inherit Theme Mods enables to copy customizer properties from parent theme to child.
Do you still need customizer properties of parent theme when you decorating new websites with child theme? 
‘Inherit Theme Mods’ can solve it. 
This plugin simply copies and inherit, or overwrite parental properties to its child. 
Also it works as an inspector of customizer properties.
<h3>Required</h3>
<ul>
<li>tested on PHP5.3 and PHP5.6</li>
<li>tested on WordPress3.9.12 and WordPress4.5.2</li>
</ul>

Inherit Theme Mods

'Inherit Theme Mods' enables to copy customizer properties from parent theme to child.

Include Parent Theme RTL CSS vs Inherit Theme Mods