I've never heard of Slack. And I don't use skype, pinterest or instagram. But I use Google Hangouts all the time. It has several features that make it better than texting. I like the idea of the hub, but in practice it doesn't do anything for me. It doesn't handle my email properly (I want it to send "from" my own domain, even though I buy email service through an ISP) and it doesn't do hangouts, and it DOES get swamped with every little notification Facebook might sent out.