And what I'm reading is that it's a bit of the PITA to get Windows Phones up and running on ST. You can get most of the functions working, except MMS on Nokia phones is a challenge. You need to access to a Nokia App called "Network Setup" that lets you adjust more settings that aren't part of the APN options. It was published to the App store at one time, and then pulled. Then published again. And I can't find again...although that could be something that you need a Nokia phone to be able to see. Just know that there's a few extra hurdles than just popping in an AT&T sim from ST and then adding in the att.mvno setting in the APN setup.