Quick question. I use to have the Iphone with AT&T. I switch to a Blackberry with T-mobile cause they offer a UMA network that works only off WIFI. The reason I need this is because at home I have no service due to living in thew middle of nowhere. So on my Blackberry i can still send and receive texts and make phones calls and such. A friend of mine was telling me that his Iphone can do this to but when I had mine it never did? So can you use an Iphone on just wi-fi send a receive texts and make phone calls with out an app?