Polymail - Native email app for email productivity.
Brand Colors - A color collection available in sass, less, stylus and css
Airmail - Airmail is a lightweight and lightning fast mail client for Mac.
Material Colors Native - Material colors native app for OS X
Spark Mail - Spark helps you take your inbox under control. Instantly see what’s important and quickly clean up the rest. Spark for Teams allows you to create, discuss, and share email with your colleagues
Mediamodifier - Create beautiful designs and product mockups in seconds.