Google shut down the invitation queue for its new social network service Google+ hours after it became available for public beta testing. It launched with an Android app available but nothing for the iPhone. However, Google submitted a Google+ for iPhone app for approval by Apple. So, the odds are it will be available in the App Store by the time Google starts allowing more people to try Google+.
Google+ for iOS Awaiting App Store Approval (Mashable)
There is some question about how full featured the Google+ iPhone app will be compared to Android. The unidentified blogger at Google+ Info speculates that Apple may not allow some functions on the iPhone: There’s the added advantage of Android having the auto-upload option for photos, which can be quite awesome — and Apple will almost certainly deny for the iOS app.