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?

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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.

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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.