Gfycat: GIFs for Gmail - GIFs at your fingertips everywhere you use Gmail
Ouch! Illustrations by Icons8 - Professional, perfectly matching, and customizable illustrations for any designs
GIPHY for iMessage - The easiest way to share all the GIFs in all your txts
Control Illustrations - 108 free flat illustrations with customizable characters
Rif - Product Hunt for reaction GIFs
Humaaans - Mix-&-match illustrations of humans with a design library.