Mozilla UI Engineer Lucas Rocha, in a post to his blog earlier today, announced Firefox's "biggest UI change … since [its] first native release back in June last year."
The UI update, Rocha explains, includes a completely redesigned and rewritten Awesomescreen, which combines the interactive and functional aspects of the start page and the old Awesomescreen into one page with super-smooth swipable tabs. For those who aren't familiar with Mozilla's mobile browser, the Awesomescreen allows users to quickly get a handle on their bookmarks and browsing history.
As the post notes, the new interface is indeed much lighter, cleaner, and smoother than before.
Right now, the new UI is only available to users of Mozilla's Firefox nightlies for Android, and there are still a few kinks here and there. According to the post, the mobile front-end team will be focusing on polishing it for Firefox 26 "in the next few weeks."
Thanks, Sadık Atalay!