Conversational UI is the hot new thing. What is it? The term encompasses not just speech-based UIs like Siri, Cortana, or Google Now, but also the use of chat bots to present products and tell stories through messaging interfaces. You can now search for a restaurant or rescue an astronaut, all by talking with an app on your phone. But where does Swift fit in? Apple's new Siri API supports only a fixed list of commands. But there is a loophole, the new iOS speech recognition API.