As a TMO subscriber, this is pure awesome. Why? Because in basement conference rooms of large hotels, museums, warehouses and the like - I have access to wifi, but my TMobile data signal is weak or nonexistent. Calls just don't work; messages (i.e. not iMessage) arrive much later and are not reliable. With wifi-calling, I will at least get my calls when I'm traveling to such areas.
7/9/14 at 11:59am