Firefox 4 App Tab

TFirefox 4 App Tabhe App tabs in Firefox 4 was a feature I hadn’t seen until this handy post from Freshbooks passed through Reeder. It was immediately one of those “how awesome is that moments.” I live in Basecamp, so that was my immediate thought. But then, oh, yeah, Pinboard, and Instapaper. Now I’m looking for other sites I routinely visit daily to add.

Speaking of Firefox 4, I was literally a day away from looking at switching to Chrome as my everyday browser, but I checked out the release candidate and pleasantly surprised by the difference. A few days later it was formally released, and I’m no longer looking to switch.

Have you found any hidden gem features in Firefox 4?