Now UI Kit - A beautiful Bootstrap 4 UI kit. Yours free.
AreYouInterested - A super-simple landing page builder for bulk idea validation
Bots UI Kit - Fully customizable Sketch UI Kit for Messenger Platform
OptimizePress - WYSIWYG page editor based on Wordpress.
Landing UI Kit - Handcrafted UI components for landing pages
Landly - Single link for all your apps