It can be downloaded in the form of device system images through developer preview site. (techone3.in)
Short Message Service (SMS) is a text messaging service component of most telephone, World Wide Web, and mobile device systems. (myintimcity.com)
So, without the Plus's additional Zigbee skills, you can control just about every mainstream smart device system already - Hue, Nest, Hive, Arlo, Ring, WeMo, ecobee, iRobot, Tile, Lifx, Logitech - the list is almost endless. (pocket-lint.com)