Like the recent YouTube update, the Google Hangouts app is taking its sweet time making its way across the entire Android platform. That means if it isn't available for your phone today, have no fear because it eventually will be available for your phone. The latest update of the app takes it to version 18.104.22.1688356 and you can try the "My Apps" section of the Google Play Store to see if the update is hiding for you there.
Considering that there aren't too many changes that come with the update, those who are anxious to install it must have a fondness for using emojis.
source: Hangouts via IntoMobile