On users’ screens, SMS conversations can be separated from the core app in the form of “Chat Heads.”

The social giant ditched SMS in late 2013 on its popular Messenger service because it didn’t think users liked it. Since then, it has invested a lot of development resources in its core instant messaging service.

Since February, select members have been invited to use Messenger as their SMS client.

Until now, however, Facebook Messenger was not offering a dual client experience. In other words, users could not combine instant messaging and text messaging.

Text messaging has experienced a sort of renaissance in recent years. Hardly missing the boat, Facebook bought a first-class ticket in late 2014 when it dropped about $20 billion on WhatsApp.

Since then, the app’s popularity has soared. In fact, it recently surpassed 1 billion monthly active users, and is presently processing more than 42 billion messages a day, including 1.6 photos and 250 million videos.

Today, thanks to significant reach in more than 20 countries, WhatsApp and Facebook Messenger stand alone as “global powerhouse" apps, according to eMarketer.

By 2018, the number of messaging app users worldwide will reach 2 billion, representing 80% of smartphone users, eMarketer expects.