I use Wireless Tags to sense and signal changes in temperature and humidity in my orchid growing rooms. All of my electrical devices (swamp cooler, mixing pumps, lights, humidifier) run off Wemo switches, Both wireless tags and Wemo switches connect with the internet, and can be (somewhat) controlled through apps on my phone.
I connect the wireless tags and the Wemo switches through IFTTT (If this then that), a freely available app on my IPhone. Thus, for example, if the wireless tag signals that the humidity is low, I can signal the Wemo switch controlling the humidifier to turn on. These three things have been very useful in controlling the environment for my orchid growing — and I can manage the environment from nearly anywhere.
However, this weekend, all the batteries in my wireless tags ran low, and the tags stopped working. This was not a significant thing, but I had to start the swamp cooler manually. They were easy to replace, but I am making this post to save the date so that next time they run out, I can find the duration of the batteries in this system, and set reminders to replace them.