As the title suggests this simple addon does only one thing, every time you logon you'll be automatically flagged as Busy. And if you become AFK for any reason, it'll restore your Busy status immediately. I did this just so I don't have to answer every whisper that comes my way.
If you find it useful for you, then, by all means, use it and abuse it ;)
Any problem, just fill out a ticket and I'll try to fix the issue asap.