Comcast's Xfinity Mobile is no longer limited to selling smartphones... provided you like Apple hardware. The carrier (whose network is run by Engadget parent Verizon) has introduced its first non-phone devices, including LTE versions of the Apple Watch Series 4, iPad Air and iPad mini. All three will cost the same as they do elsewhere. It really comes down to the cost of service. Whether you're subscribed to by-the-gig or unlimited data, it'll cost you $10 per month for every smartwatch or tablet you add to your plan.