If you download and install apps from the Play Store then you must have noticed that Google’s store uses your Google+ profile when you rate or review something. Furthermore, the Android developers have integrated the Google+ social network in Google Play services with “Google+ Sign-in”. In other words will have a better shopping experience as you can sign into an Android application with the personal information from Google+.
There are a few new features that come along with Google+ Sign-in such as OTA install from the website (you will be allowed to download applications right from the site of the developer), app customization (if you sign in with the Google+ profile you will be allowed to connect with your friends while utilizing the application, because once you sign in all the data will come along, like public profile and people in your circles), interactive posts (shares from an application now have additional functions such as check-in, listen, brand attribution, custom thumbnails; when you click on a certain interactive post the content in the application will also be linked), app activities (you can choose the people who can see your app activities).
But these are the features design for everyday usage, as there is more. Google+ Platform Insight is a function meant for app developers. The feature will allow the developers to monitor the number of downloads, total users, interactive post performance, etc.
The Google+ Sign-in is not fully functional yet because the devs will have to integrate it into their applications first. In case you are among the app devs, you can learn how to do it from the Google Developers blog.
The Google Play Store comes with another addition called Google Maps API version 2. The software comes along with several bug fixes to the map rendering.