Chat. Non-pseudonymous and therefore discoverable, universally available chat with read receipts and delivery confirmation always available. Both synchronous an

Chat. Non-pseudonymous and therefore discoverable, universally available chat with read receipts and delivery confirmation always available. Both synchronous and async conversations are first-class citizens and you can seamlessly transition between smartphone and real keyboard for more involved conversations. WhatsApp has no penetration in any social group I've ever been part of. I'll be disappointed if it does displace Facebook, because I so much prefer being able to transition a conversation to my laptop.