I ntroducing Google Allo, a smart messaging app that helps you say more and do more. Express yourself better with stickers, doodles, and HUGE emojis & text. Allo also brings you the Google Assistant, preview edition. Allo is an instant messaging mobile app developed by Google that includes a virtual assistant and provides a "smart reply" function that allows users to reply without typing. It was announced at Google I/O on May 18, 2016 and launched on September 21, 2016. The app is available on Android and iOS.