Galerías de Imágenes e Iconos
http://google.github.io/material-design-icons/
https://icon-icons.com/es/
https://www.flaticon.es/
Buscadores de imágenes
https://canweimage.com/
https://www.vecteezy.com
https://foter.com/
https://www.everystockphoto.com/
https://imagefinder.co/
https://tineye.com/
https://wunderstock.com/