A mobile version of Google Voice is now available for Android and BlackBerry users this morning, but iPhone users have been left out of the loop.  Apparently the reason for the lack of an iPhone client is all dependent upon acceptance from Apple’s rigid App Store requirements while others speculate it could be At&t holding up the release.  While we are not sure whether it is Apple or At&t causing the hold up, Google has publicly stated they would like to release an iPhone version of the application and they are “working with Apple” to make it happen, according to the New York Times.

The likely culprit causing the delayed release of an iPhone app is the possibility that Google will allow the ability to make international calls at reduced rates which would be a direct threat to At&t’s profit margin.  Add in the already free ability to send and receive text messages and Google Voice could be a nightmare for At&t if the App materializes.  At least for At&t’s sake Google Voice is still only available to invite only or for those who were previously Grand Central users and decided to upgrade their accounts.

[Via Apple Insider]