Draw with Notes on your iPhone, iPad, or iPod touch - Apple Support

Use Tags and Smart Folders in Notes on your iPhone and iPad

Use AssistiveTouch on iPhone - Apple Support

Measure dimensions with iPod touch - Apple Support

Draw in apps with Markup on iPod touch - Apple Support

Notes (Apple) - Wikipedia

iPad User Guide - Apple Support

Check your email in Mail on iPod touch - Apple Support

Take and edit photos on your iPhone, iPad, and iPod touch - Apple

Take notes on iPod touch - Apple Support

Make and receive FaceTime calls on iPod touch - Apple Support