The two main changes to Messenger are a new solid-blue navigation bar at the top with white icons for timeline, groups, people, and settings. This strip replaces the old white bar at the top with grey icons. The same goes for the status bar, which is now blue with white text and action icons.
The older design also employed a blue bar but that was located at the bottom, offering an entry point to search and start a new chat.
That feature has now been replaced by a blue circle with a plus symbol, known in Material Design parlance as a floating action button, as seen in apps such as Hangouts, Inbox, and a few others from Google on iOS and Android.
Facebook Messenger boss David Marcus announced the design makeover on social media.
"If you're using Messenger on Android, you've been wanting a brand-new material design for a bit. Any major redesign of an essential app used by hundreds of millions of people around the world is painstakingly hard, and that's why we took every precaution to ensure you'd truly enjoy this evolution," Marcus said in a Facebook post.
Facebook doesn't appear to have introduced any new features to its Android chat app.
Interestingly, as The Next Web noted, while Facebook's Messenger on Android now looks distinct from its app on iOS, employing Material Design on Android has resulted in a very similar look to Google's own Messenger app on Android, albeit in a different shade of blue.