Instant Notes is a feature of Apple's stock Notes app that enables you to make a fast note or return to a recently viewed note, without even needing to unlock your iPhone or iPad. play Subscribe to ...

Math Notes is a built-in feature that lets you crunch numbers on your iPhone, iPad, and Mac. Solve basic arithmetic and equations, create variables, and generate graphs easily with Math Notes.

How to Use the Secret Notes App Built Into Your iPhone's Calculator Work out equations and draw graphs with this useful new tool.

The Notes app may be the iPhone's most useful and commonly used app, and the ability to use it collaboratively only enhances that usefulness.

You can change your Notes settings on your iPhone using the Settings app. Changes include how notes display and how lists sort in the app.