Facebook, Instagram, WhatsApp, Messenger. I only add the latter because it's separate enough already, and you can now sign up "without" a pre-existing fb accou

Facebook, Instagram, WhatsApp, Messenger. I only add the latter because it's separate enough already, and you can now sign up "without" a pre-existing fb account. Is it similar in function to WhatsApp? Yep, but if we split the company along product lines Messenger should be considered a suitable product.