Diverse UI Overview
A free set of user images that can be used in any personal or commercial projects. Diverse UI solves the problem of finding user images for your mockups and marketing by providing you with images that more accurately represent the diversity of your user base. You can download images in any size from 32px to 180px square and pick from neutral, female or male. They have also recently added a Sketch plugin that lets you quickly add diverse user images to your designs without having to leave Sketch.