Extending the customizer
WordPress Customizer Custom Controls
WP Custom Fields is an options, metabox and customizer framework for WordPress aimed at speeding-up plug-in and theme development.
No maintenance WordPress theme
This plugin adds Polylang support for WordPress Customizer
Custom controls library. Part of the Kirki Plugin.
My sandbox to demonstrate the Customizer as default for customizing in front end.
Helper class you can use when building settings for the WordPress Customize API
A color contrast control for use with the WordPress Customizer.
Auto-magical system to style your WordPress site.
A helper package for working with the WordPress Customizer
Best Practice to decide when to use theme options page (simple or complex) or Customizer API
Enhance and extend the WordPress Customizer
Super Sexy Custom Buttons (for WordPress)—the plugin that understands your pain and delivers the bling-bling without the WTF. No more drowning in options you don't need. No more endless coding session...
Child theme for Wordpress theme Hestia to display blog entries by categories
A handy plugin to hide edit shortcuts in the customizer per user.
A WordPress demo theme showing how to use the Customize Plus plugin
Treehouse Course: WordPress