Facebook Messenger updated with Instant Video on iOS and Android
Both sides, of course, need to be running the latest build of Facebook Messenger, in order to take advantage of the new functionality. Instant Video can be initiated by tapping the camera icon, next to the VOIP call icon at the top right corner of the screen, which would previously initiate a normal video call. Doing this now, however, opens a direct video feed in a floating window, on top of the chat. Both sides can continue texting while using Instant Video.
source: Facebook
Things that are NOT allowed: