Apple has approved Google's iPhone app for its new Google+ social network, and you can download the app for free in the App Store today.
Google released the Android version right alongside the Web version a couple weeks ago.
On iPhone, the Google+ app has all of the nice features of the Android app, but with some iOS-friendly cosmetic polish. The iPhone version of Google+ also has the Huddle group text feature built in, where as on Android it was a standalone app.
Give Google+ for iPhone a spin for yourself.