Starting today, users in most countries can now use Messenger for Android as the default SMS App.
To turn the feature on, go to their settings, select “SMS” and turn on “Default SMS App.”
This will make all your SMS conversations to appear in Messenger as purple threads, alongside your blue Facebook chats. The good thing is that you will still be able to receive and read SMS in other apps, including the standard Android system.
However, do not expect the feature to show up in Messenger for iOS since iOS does not have an option for changing your SMS client.
Using Messenger to send SMS enables you to send Facebook Stickers as well as images, videos and audio as text messages.