In case you missed the news, there’s a new setting in iOS 9, that you might either love or hate. But Wi-Fi Assist could come as a big surprise at the end of the month when your bill comes. When Wi-Fi Assist is turned on (as it is by default) if your wi-fi connection is poor, your cellular data will be called on to fill the gap.  You know, I’ve been some places where the wi-fi connections were so miserable, that I have switched to cellular. But I like knowing that I’ve made the choice, so my cell phone bill isn’t a huge shock.

You’ll find this new setting under Settings>Cellular and scroll down to the very end of the section. Its also a good reminder to go through all your apps and restrict which ones can use your cellular data.