Not to be outdone by Twitter's big update today, Google has also updated its Google+ app, with support for the recent Google+ Events feature, full support for usage on the iPad, and the ability to start and join hangouts directly from the iOS interface. It's pretty snazzy -- if you're a Google+ fanatic, this is probably one of the better updates for the app you'll see.
The Google+ app is a free download, and of course joining the Google+ network is free with any Google account.