Version 1.3 of G+ Notifier (for Google+) recently went live. Unfortunately, due to an error with 1.2, you might not be notified about the update by the application unless you leave it running for 12 hours!
Here's some screenshots of the current version:
Unfortunately, with absolutely no warning, Google suspended the G+ Notifier account I'd created on Google+ to announce updates. I'd asked a number of times whether this was ok, and got no response. As a result, if you want notification of updates without all of my unrelated posts on Google+, the best way is to follow @GPlusNotifier on Twitter. Yeah, really.
Of course, if you don't mind the personal posts, the best place to follow G+ Notifier is my account on Google+.
You're also welcome to fork the code and send pull requests. It's a good idea to let me know in advance, just to ensure someone isn't already doing the same thing. There are already a few people (Adam Simmons, The Configurator and Andrew Nurse) contributing to the project!