Interfacer - Collection of more than 200+ free design resources
Slickr - Powerful cover image generator for your Hashnode blog
Facebook Design Resources - A collection of free resources made by designers at Facebook
Canva Pro - Millions of design assets, templates and images all in one
Freebiesbug - Collection of the best free web design resources.
SocialSizes - Sketch templates for sharing images & videos on social media