After the release of Google Plus a native app was already available for Android but Google Plus app for iPhone is still missing. But that is the end of the world. Not because Google Plus is not unnecessary, but because you already have the ability to use Google Plus almost as natively from your iPhone. If you are planning to use Google Plus for iPhone or iPad all you need to use is the Safari Browser. Google Plus just plays fine in your iPhone.
Google has designed the mobile version of Google Plus very effectively with HTML 5. So when you point your Safari Browser to the Google Plus site you will see a beautifully crafted app-like interface ready to use. Though this version of Google Plus for iPhone will not work as powerful as native Google Plus for Android phones it should do just fine.
Google Plus for Android phones has some impressive features. The most impressive feature to me was the instant upload of any captured picture. No need to panic! The picture doesn’t go public instantly. It just gets uploaded and waits for you to decide its fate. You can publish it, keep it or just delete it as your wish. Google Plus for iPhone is on review and it should be on its way too though I don’t think it will have this instant upload feature as it doesn’t go with the policy of Apple.