Instagram started telling you when your friends were active in the direct message list last January. Now the photo-centric social network is expanding the feature with a new green dot to indicate who is online and active.
You'll be able to see the green dot in your direct message inbox as well as your friend list when you share a post from your feed. You'll only see the status indicator for friends who follow you, or people you've already exchanged direct messages with. Just like before, you can turn this off (and hide your own status) in your Instagram settings.