ROBLOX+ is a Google Chrome extension that can change the way you use ROBLOX.
Made by WebGL3D, ROBLOX+ is a very popular extension that enhances the ROBLOX website, not the games. It is very useful for everyday ROBLOXians.
There are about 50 features.
What I like about ROBLOX+ is that you can send a message to up to five people, get notified when you get a message, trade request, group shout, etc., you can add YouTube videos to forum posts, and you have a customized inbox. You can even search for messages!
Download ROBLOX+ by going to http://roblox.plus or looking at the how-to-download video below: