I purchased the thermometer for my mother, who is running iOS7 on both her iPad and iPhone and the setup was awkward, but pretty straightforward, as it walks you through the process. Unfortunately, the thermometer doesn’t seem to reconnect to the wifi after it sleeps/powers down. The app cannot locate it and you must go through the entire setup process again. Very disappointing, but hopefully it will be resolved at some point in the near future and I will purchase it again for her.
ChadSchex about Williams-Sonoma smart thermometer