Over the last year, Meta has added AIM status-like features to Instagram and WhatsApp and today announced it's rolling out Notes (using the same name as Instagram’s feature) for Messenger globally.

You can’t post them from the desktop, but a support document explains how to add or remove Notes via iPhone, iPad, or Android device by clicking the thought bubble next to your profile picture. If you don’t remove them manually, the messages expire after 24 hours.