Apple's latest mobile operating system, iOS 9, may bring a fresh set of features to its massive user base. However, there is one feature, enabled by default, that might make iPhone users go over their data limit. Wi-Fi Assist would appear as a helpful feature at face value. But its functionality might not be to its users expectations.

Wi-Fi Assist, a new feature that came in with the iOS 9 update, will switch networks to cellular just in case Wi-Fi connections are flaking out. Now, this would be a very handy feature should the iPhone user be on an unlimited data plan. Otherwise, Wi-Fi assist would more likely make users concur more data charges and an undesired expensive carrier bill.

There is an indication whether Wi-Fi Assist is active or not. It is rather easy to tell. The Wi-Fi icon will be grayed out and from there will be your discretion to use your cellular data. However, indications are not the problem. It is taking notice of it. Most users have thought that they are still on their Wi-Fi network, but then later finding out that they are on cellular data.

Samsung's Galaxy S5 also has a similar feature built in to it for a while now, called Smart Network Switch. However, the feature is not enabled by default, as the device will first prompt its users should they want to switch to cellular data. Therefore, they would not be caught off guard should they want to deliberately be charged on concurring cellular data usage.

It is unclear if Apple will be turning it off by default when the next update arrives. However, it would have been helpful if they managed to turn it off by default. Many users have already gone over their data limit, after all.

To disable the feature, users can go to the Settings app, open the Cellular menu, and from there scroll to the bottom of the screen to find the toggle "Wi-Fi Assist."