Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
Interfacer - Collection of more than 200+ free design resources
Icons8 Lunacy - Free graphic design software with built-in resources. Fully compatible with Sketch and works offline
Blush - Illustrations for everyone
Adobe XD - Adobe XD is an all-in-one UX/UI solution for designing websites, mobile apps and more.
Freebiesbug - Collection of the best free web design resources.