Watch2Gether - Watch2Gether is an app that allows multiple people to watch the same content simultaneously and interact with each other while watching.
TogetherTube - to watch videos with other people online
Syncplay - Syncplay is a different kind of entertainment platform.
Rave - Rave is a free iOS and Android app where you can watch Netflix, Disney+, YouTube, Prime Video and more while chatting with friends in perfect sync. It's the ultimate virtual movie theatre!
ShareTube - Watch YouTube, synced with friends.
CyTube - Free, open source synchtube