Facebook’s family of apps are moving in together. Facebook, Messenger and Instagram are each testing a feature that shows notification counters from the other apps and lets you instantly switch between them.The feature could boost engagement across the apps by using those maddening red notification jewels to constantly remind you there’s something to see in the other apps. This way if you miss or dismiss an alert when you first receive it, or you don’t get push notifications from every type of activity, you’ll still see that red number lingering in the corner, beckoning your attention.That’s also why some users will probably hate it. It exploits people’s anxiety about unread alerts and red dots in their blue apps to compel them to action.

Source: Facebook, Messenger and Instagram unite with cross-app notifications | TechCrunch