Many Google+ users flocked to download the newest version of the social media networks app when it was announced only to find that it was incompatible with their version of Android (the newer versions). After a few hours, the Google+ team has rectified this issue and it's now available for users running the newer version of Android, including Jelly Bean.
The Google Play store still states that the app requires Android versions 2.2-2.3.7; however, Jelly Bean users are no longer receiving an error message when attempting to update the app.