Source Wireframe Kit - Library of 537 blocks for desktop and mobile prototyping
Humaaans - Mix-&-match illustrations of humans with a design library.
Form Wireframe Kit by InVision - A free wireframe kit from InVision
Control Illustrations - 108 free flat illustrations with customizable characters
Contra Wireframe Kit - Open source wireframe kit for design and prototyping 🚀
Ouch! Illustrations by Icons8 - Professional, perfectly matching, and customizable illustrations for any designs