To get at the general settings for Signal, from the Chats tab tap the three dots (top right) then Settings on Android, or tap your profile picture (top left) and then Settings on iOS. You can change a number of options from here: Choose Appearance, for example, and you’re able to change the app theme, colors, and icon.

Unlike other popular messaging apps, Signal is operated by a non-profit called the Signal Technology Foundation rather than a for-profit tech giant like Meta, which owns popular messaging apps like Instagram and WhatsApp, or Apple, whose iMessage platform is available across the company’s devices.

Signal is the most secure messaging app for your smartphone, but a recent leak from a US government chat group has raised questions. So how safe is Signal and how do you use it properly?

With news this week of the messaging app being used to discuss war plans, we get you up to speed on what Signal should be used for—and what it shouldn’t.

Is the Signal messaging app really less secure than government systems? NBC News’ Kevin Collier explains Signal’s strengths and limits after an Atlantic magazine editor was accidentally added to a group chat where President Trump’s Cabinet officials discussed military plans.