Pretzel - Keyboard shortcuts for the app you're currently using
Design Principles - An open source repository of design principles and methods
KeyCue - Menu shortcuts are supposed to provide quick access to frequently used menu commands.
Facebook Design Resources - A collection of free resources made by designers at Facebook
Alfred - Alfred is an award-winning app for macOS which boosts your efficiency with hotkeys, keywords, text expansion and more. Search your Mac and the web, and be more productive with custom actions to control your Mac.
Facebook - Connect with friends, family and other people you know. Share photos and videos, send messages and get updates.