https://wccftech.com/gmails-smart-compose-feature-now-available-to-all-android-devices/

Smart Compose is essentially Smart Replies for Emails. Instead of cold, robotic canned replies, we get full sentences. We got out first look at Smart Compose for Gmail at I/O 2018. The feature then made its way to web versions of Gmail followed by G-Suite users. Smart Compose predicts commonly used phrases and attempts to complete your sentences, based on your typing patterns. It was meant to be a Pixel 3-only exclusive, but it looks like Smart Compose is making its way to all versions of Gmail on Android.

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