Among the feature additions in the latest Hangouts update is the ability to switch between Google Voice and carrier SMS without diving into the app settings. All you have to do is tap on the "spinner," the toggle in the conversation window that already allowed you to alternate between Hangouts and SMS. Now, provided you have a Voice and carrier number, you'll have two SMS options.
Previously, the default setting was for Hangouts to automatically choose the number you had most recently used for the contact. You could also just choose one or the other in the SMS settings menu. If you use Voice for voicemail, you may have noticed that receiving a voicemail from a contact would cause the "smart reply" default setting to change your SMS number to your Voice number. That has definitely led me to confuse more than a couple of my contacts when I accidentally messaged them from a number they had never seen before.
As you can see in the screenshots above, switching back and forth is now very simple. This may not affect the majority of Hangouts users, but for those who need it this will be a major improvement to usability. Perhaps more important is that this is yet another positive sign for Google's continuing integration of Google Voice and Hangouts. For more info on the app update as well as an APK download, check out our earlier post on the topic.
Thanks Mayur Kamat