In addition to the Gmail app, Smart Reply is available on Inbox by Gmail and Allo. Our reaction to Smart Replies has been mixed. The replies are definitely impersonal and sometimes the suggestions can be a little off (though it supposedly gets better over time because machine learning analyzes your replies). But according to Google, 12 percent of Inbox users take advantage of the convenient replies, so clearly people find them useful. And let's face it, if all you need to say is a quick "Thank you," why not use a canned response?