An instant messaging app from Google for Android and iOS mobile devices. Introduced in 2016 by invitation only and integrated with the user's phonebook, Allo supports disappearing chats and encryption. By swiping, Whisper Shout makes text size tiny to avoid prying eyes or very large all-caps for emphasis. If a recipient does not have the Allo app, an SMS text message will be sent. Google Assistant Is Ever Present Allo is one of the first Google products to use its latest virtual assistant, which can interject "smart replies" as a response to a message and becomes more useful after gaining experience with the user's mobile habits. Assistant can also be used directly within Allo just as a personal assistant. See Google Assistant, instant messaging, virtual assistant and Google Duo.