If you remember correctly, T-Mobile's Uncarrier pricing structure offers very inexpensive monthly payment plans for service, but then instead of subsidizing the phone price, you make monthly payments on the devices after paying a $100-150 dollar initial fee. It looks like T-Mo wants to go a step further and entice users with a pretty awesome deal. You can grab any one of several excellent devices for $0 down and the usual payment plan for a limited time. The device choices are: LG G2, Samsung Galaxy Note 3, Samsung Galaxy S4, and the Samsung Galaxy Note 2. As you can see, many of these are the latest and most powerful smartphones on the planet.
Keep in mind, T-Mobile isn't being completely altruistic. Paying no money down means that your monthly payments will be a little bit higher. Still, for folks who find it hard to come up with the initial down payment, this is a very attractive offer.
Here's a link directly to T-Mobile's website where you can check out this deal: Cell Phones | 4G Phones | iPhone and Android Phones | T-Mobile