Its a QOTO feature and yes you can access it from our web client.
It lets you follow a user without them knowing you are following them and without them needing to approve of you as a follower if it is locked down.
The down side is you will only see their public posts and any follower-only posts you cant see unnless you follow.
@davoloid thanks. so that part is similar to twitter. what's the difference between follow and subscribe if you don't mind explaining? when I search for someone these are the two options.