Humaaans - Mix-&-match illustrations of humans with a design library.
Circuito.io - Instant code and wiring for your project
Control Illustrations - 108 free flat illustrations with customizable characters
library.io - Learn electronics and easily create circuit boards online
Ouch! Illustrations by Icons8 - Professional, perfectly matching, and customizable illustrations for any designs
B4R - Development tool for native Arduino programs.