During the weekend I have been tested the Chrome Extension application #oSteem.
First of all, I found this application very useful. I think that all of us are following many people and if we want to see only the posts of a bunch of people (close friends) this is not possible.
I am sure that in few years Steemit platform will get new interesting features.
Until now the application is not very friendly, but the 
I think that the area added by oSteem fits very good into the Steemit environment.
If you log in for the first time on Steemit you won't guess this add-on is not from the core application. After the chrome extension installation, it appear in right corner on top, beside "Tags and Topics".
Adding and deleting users work fine, but if I didn’t get the instruction before, I didn’t know how to remove the user from vip users list. Actually, if I was thinking that this application is made by a programmer and how is he thinking, I could guess after a few attempts.
After pressing the “Enable vip” button and refreshing the page everything works fine. My page was filtered and shows me all posts belonging to vip users.
To load many posts, you have to scroll down. Maybe you'll think you are facing a bug, but I don't think it is: Steemit as any other social network platform is progressive loading the posts in order to avoid the overload.
After a while I saw that the page is not filtered sometimes, all posts were displayed. I don’t know why and I didn't found a pattern to say exactly when it happens.
I hope my post will help you and I am waiting for bug solving and the new features.
I was thinking about some enhancements, but I will tell you later, after a new version.