UI8 - Carefully crafted UI design assets
Source Wireframe Kit - Library of 537 blocks for desktop and mobile prototyping
Handsome Illustrations - Create unique illustrations for websites & applications.
Contra Wireframe Kit - Open source wireframe kit for design and prototyping 🚀
Ouch! Illustrations by Icons8 - Professional, perfectly matching, and customizable illustrations for any designs
Platforma - Wireframe library of layouts and UI elements