UserInterface.io - Weekly UI/UX tips in your inbox for free
Craftwork - A collection of User Interface resources made by Craftwork
Fabrx.co - Create the UI Kits, Bootstrap 5 or HTML Dashboards that you need in minutes. Have some design sense to spare? Fabrx will help you tackle even the trickiest of projects.
Carrd - Simple, responsive one-page site creator.
Supernova V4 - Turn Sketch into iOS, Android and React Native in minutes
Facebook Design - Resources for Designers from the Facebook Design team