All Talk and No Buttons: The Conversational UI

We're witnessing an explosion of applications that no longer have a graphical user interface (GUI). They've actually been around for a while, but they've only recently started spreading into the mainstream. They are called bots, virtual assistants, invisible apps. They can run on Slack, WeChat, Facebook Messenger, plain SMS, or Amazon Echo. They can be entirely driven by artificial intelligence, or there can be a human behind the curtain.