Allo is an instant messaging mobile app developed by Google. 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. Contents 1 History 2 Features 2.1 Smart reply 2.2 Incognito mode 2.3 "Whisper Shout" 2.4 Google Assistant 3 Reception 3.1 Optional encryption 3.2 Message retention History Allo was announced at Google I/O on May 18, 2016 . At the time, Google said that it would release Allo in summer 2016. Google launched the app on September 21, 2016. Features Allo is based on phone numbers. Smart reply Allo's "Smart reply" function uses Google's machine learning technology to suggest a reply to the last message, which can be selected from a few options. The feature also analyses images sent to the user in order to suggest responses. Similar to the smart reply feature seen in Google's Inbox app, it learns from the user's behaviour to ...