With an iPhone, you don't need to download an app like Signal to write and send secret messages: All you need to do is open up your Notes app. Read more: iPhone 16: What We Know About the Release ...

Messages can solve simple math equations like "2+2=" by typing them into the text field. The app can also solve equations ...

Unlock 20 hidden iPhone tricks to boost efficiency, personalize your device, and discover features you never knew existed.

But a different feature entirely was added in a recent iOS update—‘Critical Messages’—that enables apps to send your iPhone highly important messages via SMS. Here’s how it works.