In Nexus 5, Messaging app is gone. This is ported from original android Lollipop 5.0 open source. It will separate you messaging from hangout app.
It provides different colored theme based on latest Material Design used in android Lollipop 5.0
• Various SMS template with emoji are added in a nice way in the keyboard itself.
• Messaging app that separate you from hangout specially on Nexus 5.
• Support Android Kitkat - 4.4
• Support Android Lollipop - 5.0
Note:To use Kitkat SMS separately from google hangout application please set this Kitkat SMS as your default SMS app.