* mouse-clickable button: APIs for handling the fullscreen state of browsers are still nascent (Chrome 15 and Firefox 9-ish?), so it's a matter of months until adding it;
* Chrome Web store: already on the to-do (plus 100% offline usage via HTML5 manifest).
So I'm reluctant to invest any time in it. You need to stay around and make me come back.
The F11 thing is clever, but please also add a mouse-clickable button.
The name also probably means something relevant, but it's impossible for me to remember.
Here's an idea: get listed on the Chrome Web Store. If I install your app from there, I'll see it every time I start Chrome.