GitHub - makeitworkpress/wp-custom-fields: WP Custom Fields is an options, metabox and customizer framework for WordPress aimed at speeding-up plug-in and theme development.
GitHub - mustafakucuk/tutty-meta-box: Create custom fields with simple and easy to use WordPress meta box framework.
Meta Box - WordPress Custom Fields and Custom Meta Boxes Framework
How to Add Testimonials to WordPress with Meta Box | by Janessa Tran | Meta Box | Medium