The Hangouts™ app lets you send and receive video calls. To open it, touch 
Hangouts on a Home or 
All Apps Screen.
To start a video call:
- Touch
Add at the top of the main Hangouts screen and start typing a name, email address, or phone number. Matching names and numbers from your contacts appear as your type - Choose a name, then touch
Video at the top of the screen.
To adjust notification preferences and other settings, touch: 
Menu > Settings