I would ignore the low reviews here as these folks just dont seem to know what they are doing or cant follow instructions. The instructions specify that you need to be using iOS 6.0 or later. My unit connected flawlessly on the first attempt and I even powered down my thermometer AND iPad Air and when I powered everything back up everything reconnected automatically. I am very much looking forward to actually trying out the functionality of the smart thermometer and app!
Erik in NJ about Williams-Sonoma smart thermometer