Another option if you’re going to want multiple sensors is the kumostat wireless tags. You have to buy their ethernet bridge, which is about $40. But the individual sensors, which are very well engineered, run as low as $29. And their multisensor, which includes motion detection, is $39.
So if you’re going to want more than 4, The Kumostat end up being less expensive than even the everspring zwave model. But the set up is more complicated.
Kumostat also has a nice IFTTT channel which gives you additional indirect integration options.
