The gPlus app for Google+ has been updated (v. 1.1.1), and it now includes access to the Communities! gPlus is really the only functioning client app for Google+ on Windows Phone 8 that I am aware of, as all the others I've tried are basically a wrapper for the limited mobile web interface to Google+.
gPlus | Windows Phone Apps+Games Store (United States)
The app is still a bit rudimentary and wonky, with inconsistent navigation and formatting issues (sometimes html codes appear instead of bold/italic fonts). But at least it can be used to access posts in the main Google+ stream, your circles, and communities you belong to.
In a post on Google+ the developers indicate they are also working on a version for Windows 8.1 as well as Windows Phone 8.1, which will use oAuth login.
https://plus.google.com/101767966522661730111/posts/VEwZfhstWLE
So there's hope for those who are looking for a functional Google+ app on Windows Phone!
gPlus | Windows Phone Apps+Games Store (United States)
The app is still a bit rudimentary and wonky, with inconsistent navigation and formatting issues (sometimes html codes appear instead of bold/italic fonts). But at least it can be used to access posts in the main Google+ stream, your circles, and communities you belong to.
In a post on Google+ the developers indicate they are also working on a version for Windows 8.1 as well as Windows Phone 8.1, which will use oAuth login.
https://plus.google.com/101767966522661730111/posts/VEwZfhstWLE
So there's hope for those who are looking for a functional Google+ app on Windows Phone!