The planned integration of Facebook’s messaging applications has started. In its biggest step so far, the company is allowing select users on Messenger and Instagram to message one another, app to app.

The change will make messaging across two of the company’s products easier. For example, people who use Instagram can now send messages, photos or videos to those use Facebook Messenger, and vice-versa. It’s happening without having to switch between apps.

The two apps — Facebook and Instagram — will continue to operate separately but at the same time, there is an indirect connection.

“More than a billion people already use Messenger as a place to share, hang out and express themselves with family and friends. That’s why we’re connecting the Messenger and Instagram experience to bring some of the best Messenger features to Instagram — so you have access to the best messaging experience, no matter which app you use,” Adam Mosseri, head of Instagram, and Stan Chudnovsky, head of Messenger, has said in a jointly-written post.

Facebook has announced that it would also add 10-odd features to Instagram that were previously exclusive to Messenger, such as group video watch sessions, an ephemeral messaging mode and “selfie stickers”. Watch Together is particularly interesting as it lets you watch trending videos with friends on IGTV during a video call.

At the same time, messages and calls from friends and family using Instagram will continue to stay in your Instagram app. The main change is that people using the Messenger app can now reach you on Instagram without you needing to download a new app. There is also a way to control where you receive messages and calls. For example, in your chats, in your message requests or, for that matter, you can even refuse to accept messages.

More than 100 billion messages are sent across Facebook’s family of apps every day, according to Chudnovsky. This is far greater than the 24 billion SMS text messages exchanged daily on mobile carriers at their peak around 2015.

The plan that is being implemented was announced by Facebook CEO Mark Zuckerberg last year. He had discussed his intentions to integrate the social network’s messaging services — WhatsApp, Instagram and Facebook Messenger. According to The Guardian, WhatsApp will continue to remain a separate, end-to-end encrypted app at this time.

The new features on Instagram and Messenger are being rolled out in “a few countries” and will be “expanded globally soon”.