Video Hangouts no longer require a Google+ account

We would point out though that you were never really forced to use Google+ as some believe. For a while there, Google+ came as an automatic part of a Google account, but all that really meant was that you had to use a name that looked real (even if it wasn't). Actually using Google+ was never a requirement. However, Hangouts was born in Google+ and so it makes sense that it would have been connected to the service at first. Now, Hangouts has broken out and exists in Gmail and as its own app on Android and iOS, so Plus isn't necessary. 

So, Google Apps users and those without a Google+ account can use Hangouts to video calls with up to 15 people. You can also create, edit, or join a Hangout from a Google Calendar entry, which is pretty nice. This is part of the new Hangouts update that has pushed out to both Android and iOS, so if you have version 2.3 on Android, or version 2.2 on iOS, you'll be good to go. 

source: Google via Droid Life