Yes I understand that my title is slightly confusing, but I would like to know whether anyone has been able to get WiFi calling working on a phone plan like simple mobile(which I use), straight talk, or metro PCS, all of which run on the T-Mobile networks, and on T-Mobile locked devices. I'm asking because I heard that the 925's WiFi calling feature is strictly limited to T-Mobile only, which I find hard to believe because all the plans listed above run on T-Mobile networks. I conducted a little test of myself by asking a T-Mobile customer representative if my phone number would transfer over to T-Mobile if I switched, and she said that my number was already listed under T-mobile.... That seems to provide enough evidence, but I would like to make sure before I go out, and purchase a 925 for myself. I'm currently a college student living in a basement apartment, and I get little to no reception on my Lumia 810. I'd also like to upgrade because T-Mobile doesn't seem to be planning on delivering the Blue, or even Black updates in the future. There aren't any new Lumia's coming out for T-Mobile anytime soon, right?