Get a Hangout App for your Chrome to keep you update with the messages which been send and receives for you .
How to Get app , follow the following steps .
Step 1 : Visit the following link : https://hangouts.google.com/
Step 2 : In left hand-side menu more icon which is represent by three dots …
Step 3 : In the sub menu, click over Chromes from App downloads section
Step 4: A pop up window will show up as picture below , Click over Add app
Step 5: When you go to Google Chrome Apps by type chrome://apps/ in address bar , you will find hangouts app waiting you to lunch it .