Design Principles - An open source repository of design principles and methods
Roboflow Annotate - Annotate images with ease. Export to any format.
Facebook Design Resources - A collection of free resources made by designers at Facebook
Drift - A messaging app that helps you grow your business.
Facebook - Connect with friends, family and other people you know. Share photos and videos, send messages and get updates.
Good Annotations - A online annotation tool that is perfect for providing feedback to your team.