I know postpaid customers can now place calls through WIFI without using minutes but I am advised WIFI calling still deducts minutes from prepaid customers. Can an 'adjustment' be made to T-mobile's wifi calling app or to the phone to place free WIFI calls or are there third party solutions that allow a prepaid customer to place free WIFI calls? I will be using Android or Windows Phone 7.5. Do any current smartphones include the UMA hardware?
To clarify, I am not talking about VOIP over T-Mobile's cellular data network.