If you're having trouble installing the UberConference Hangouts app, please check the following:
Make sure you have a Google Plus account created for the login you use to access Hangouts. You can verify this by going to http://plus.google.com and create one there
If you are part of a managed Google for Work account, additionally make sure your Google admin has enabled both Google+ and Google Talk/Hangouts for your company
Go to UberConference.com/Hangouts and install the UC Hangouts app from that page
- Start a video call in Hangouts. You should see the app load in the left nav.
If you've recently upgraded your Hangouts app and want to switch back to the original video call interface, check out this help article from Hangouts.