Doodle Ipsum - Doodle Ipsum is a free illustration tool for devs powered by Blush!
Handsome Illustrations - Create unique illustrations for websites & applications.
Illustration Kit - Premium open source illustrations updated daily
Control Illustrations - 108 free flat illustrations with customizable characters
Ouch! Illustrations by Icons8 - Professional, perfectly matching, and customizable illustrations for any designs
Humaaans - Mix-&-match illustrations of humans with a design library.