Themify Flow - Drag & drop Wordpress theme builder
Dashboard UI Kit - A modern & responsive dashboard UI kit for designers.
Layers - A simple Wordpress site builder & its free forever
Bots UI Kit - Fully customizable Sketch UI Kit for Messenger Platform
Elementor - Elementor is a front-end drag & drop page builder for WordPress.
Now UI Kit - A beautiful Bootstrap 4 UI kit. Yours free.