According to the registration form on the site, Smart Reply is simply called "Reply" and is scheduled to be available to Android users in the near future. According to the e-mail sent to early adopters, Reply will first visit Google Hangouts and Android Messages. Respond smartly to questions like "Are you at the restaurant?" And "When do you get home?"
These replies will be combined with the user's current location to reply, if you have arrived at the destination then may reply "yes", if you have not arrived at the destination, then it is possible to estimate the arrival time based on the current driving style and distance.
According to the project announcement for Area 120, this feature will provide support for a variety of mainstream chat applications including Hangouts, Allo, WhatsApp, Facebook Messenger, Android Messages, Skype, Twitter DMs and Slack.
Reply also includes other automation features. For example, a user switches to Do Not Disturb mode while driving, keeps the phone muted, and alerts people who can not chat with you.