What is the Messenger and what does the Messenger do?

Facebook Messenger is a FREE mobile messaging app used for instant messaging, sharing photos, videos, audio recordings and for group chats. The app, which is free to download, can be used to communicate with your friends on Facebook and with your phone contacts.

Is it safe to use Messenger for SMS?

While Facebook Messenger is not end-to-end encrypted by default, it is more secure than the fragmented SMS architecture operated by the networks. Yes, whenever a recipient is only on SMS this becomes moot, but youll find many more of your contacts on Facebook Messenger than Signal.