Because you obviously aren't using Instagram enough, the Facebook-owned service has added a helpful new feature that should make it even harder to ever leave its interface.
From now on, a green dot will show up on in the bottom right corner of the profile pictures of the people who are currently online and using the app. The dot will be seen in Instagram Direct as well as your friend list when you share a post from the feed.
According to Instagram, the dot will let you know when your friends are available to chat. And we assume the hope here is that you'll use Direct instead of hopping over to Facebook Messenger or WhatsApp to have those conversations. It's just a tad ironic that all three of these services are Facebook subsidiaries.
On Instagram, you can choose to hide your own status as well as turn off the ability to see when your friends are active. Note that you will only ever see the green dot for friends who follow you or people you've already talked to in Direct.