hello, since a couple of days t-mobile has release wifi calling for the nexus6!! but i have a few questions. Would an unlock AT&T, Play store phone also work with wifi calling? or do i need to buy it from t-mobile? How do you activate it? i currently have t-mobile on my iphone 5 but might change tu nexus ;D Do text also go over wifi? thanks in advance UPDATE not sure if i should create another thread but same question for the sony z3!