Google Product Forums
Re: Why doesn't gmail talk work on my iphone4?
Craig Long Apr 28, 2012 2:30 PM
Posted in group: Google Chat

Categories: I found a bug! : Text Chat : Gmail :

See this response from a Google employee KatherineG:  https://groups.google.com/a/googleproductforums.com/forum/#!starred/chat/BjmLgrLhiA8
Try this:
Talkatone for Android and iDevices--Unlimited FREE calls, texts and picture sharing to GTalk friends, or any phone number in US/Canada: