If you haven't already been scared off by Edward Snowden's doom-mongering, Google Allo is certainly an interesting proposition that's worth a look-in.
It's best described as a smart messaging app which will eventually enable you to reply to messages without needing to type a single word. Allo's Smart Reply technology effectively learns over time and suggests responses to text and photos, in your style.
An early iteration of the Google Assistant is also built into the Allo app. The bot functions as your very own personal assistant, and you can set it to task by finding restaurants nearby, sharing videos or use it to gather answers to questions.
Like Chrome, Allo includes an Incognito Mode that allows you to send messages with end-to-end encryption, and control how long your messages stick around with expiring chats.