Looking For App That Can Turn Image On/Off On Website

[googolga]

Hi all,

I am new to the forums but have been reading ModMyi for a while and have learned so much and gotten the heads up about so many great apps, so I'm hoping someone will be able to help me.

I'm looking for a simple, free app that basically has an "on/off" switch (or something similar like "available/unavailable" or "online/offline") that controls a widget or an image on a website. In other words, when I open the app and say that I'm "online," I want an image or widget to appear on my website, and when I'm "offline," then I want a different image/widget to appear (or no image at all).

I know that something like this exists, because the popular chat application Zopim (www.zopim.com) allows for this -- if you're online, the chat box pops up on your website, and the moment you say that you're "away" on the app, the chat box disappears.

Really hoping someone can point me in the right direction here... Thanks in advance for your time!