Facebook has been working on a bottom bar for its Android app for quite some time now. Last year, we saw a wild redesign that added a big "F" menu button in the middle, flanked by quick access to the news feed and notifications. That design appears to have been shoved back into the drawer, making way for a new experiment that looks much more conventional. The latest A/B test just takes the familiar top section bar and moves it to the bottom of the screen, which doesn't look too different from the iOS app.
Once you get in on the server-side change first spotted by XDA Developers, you'll be greeted by an introduction that explains how "Shortcuts are now within reach at the bottom of your screen." That includes all the standard sections like the news feed, notifications, and the menu as well as the usage-based custom shortcuts, like groups, friend requests, your profile, and more. The search bar remains at the top app bar. It's unclear whether or not you'll still be able to swipe between the section.
The interface first popped up in version 2184.108.40.206.111, but when we tried installing that one or a newer release of the Facebook app, we couldn't see the new bottom bar — it's likely a server-side change that's just starting to roll out, as people on Reddit report. You can still try getting the latest stable version from the Play Store or APK Mirror to see if it works for you.
- XDA Developers