The Google+ iPhone app is now the number one application in the App Store, less than a day following its release. The application allows users to access Google+ in a native iPhone app, provided users have already been invited to use the social network. Unfortunately, the application is not yet compatible with iOS 5, meaning iOS developers running a prerelease version of the upcoming mobile operating system will have to stick with the mobile Web version of Google+, for now.

Following the release of the Google+ iPhone app, Google noted that the wrong version of the application had initially been released, which resulted in a poor, buggy experience for some users. In order to correct this issue, Google advised that users delete and reinstall the application from the App Store: Provided your version number is 1.0.1.1809 things should run fine.

(This does’t fix the iOS 5 issue, unfortunately.)

Now, back to the application’s success in the App Store: Less than 24 hours following the app’s release, Google+ for iPhone became the number one free application in the App Store. As Alexia Tsotsis of TechCrunch notes, the top free iPhone app of all time is the Facebook iPhone app, meaning “Google+ is in good company.”

Despite the social network’s limited launch, Google+ has already accrued around 18 million users. It would appear that once Google+ goes public, the social network is going to prove to be extremely popular. The main question, however, is whether Google+ will stand the test of time.

If you’re a Google+ fan, take a look at the free iPhone app now. And don’t forget to follow AppAdvice on Google+ via this URL: http://gplus.to/appadvice.