One thing that was already great about the Google+ app is that it includes an Instant Upload feature, which automatically backs up pictures and videos taken by your Android device. By default, these items go into the private "From your phone" album, where you can easily access and share them at your convenience. Of course, you can disable Instant Upload if you're worried about battery drain, but I think it's a superconvenient feature that should be taken advantage of.
Communities
The Communities section lets you manage the news items and hobbies you follow. You can share communities you like with your friends or invite them to the community directly. You get display counts for unread messages in your communities and the moderation tools have been improved as well.
Events
Here, you can manage your own events as well as those to which you have been invited. With a single tap, you can start setting up a new event, complete with date, time, invitees from your circles, and even a location tag.
If you like, you can set the Google+ app to automatically back up your mobile photos to a private album in the cloud.
(Credit: Screenshot by Jaymar Cabebe/CNET)Hangouts and Messenger still evolving
Google recently released a standalone version of Hangouts to replace Hangouts and Google Talk. If you select Hangouts in Google+, you'll automatically be redirected to the download at the Google Play store. Messenger still lets you chat with one or more of your Google+ connections from a single panel in the app, but also advertises Hangouts at the top of your Messenger screen. I suppose Messenger will probably stick around for quick chats in Google+, but Hangouts seems to be moving completely off the app. Perhaps Hangouts is being left as a menu item for now as a transitional phase while Google moves people to the Hangouts app, but we'll have to wait and see what happens in the coming months.
Conclusion
Overall, the Google+ app provides an excellent way to interface with the Google+ social space while on the go, whether you're on a smartphone or tablet. In the new version, the interface has been cleaned up significantly, and new photo tools let you make quick edits and apply filters, mostly obviating the need for other photo editors. The Hangouts and Messenger features seem to be evolving in light of the new Hangouts app, so while a little confusing, this transitional phase is understandable. In the end, whether you're a regular Google+ user or you're just interested in the additional photo-editing tools, you don't want to miss the Google+ app for Android.