web page Firefox plugin or extension

I'm building a small web app that should run in the background while the user browse the web, a dynamically added Iframe isn't an option since I can't reload it anytime the user refresh or switch page.

while on Google Chrome this is pretty easy to accomplish, I can't find anywhere an example or documentation on h开发者_StackOverflowow to implement that on Firefox

I guess what I'm really after is a method to open a non depended totally chrome-less frame (which will run my web app and stays there even if the users switch or refresh pages)

Any Ideas?

The best way would be to add a listener for when the browser changes the url and then communicate with ajax the data you want.

The closest thing that matches your description is hiddenWindow, which is an undocumented and unsupported way to have random webby content in a window not displayed anywhere in UI.

If you said what exactly you're trying to do, you'd get more useful answers.