How can I turn off cellular data for an iOS app?
iPhone and iPad users who are watching their data usage might notice that some apps are data hogs. While the data allotment might be limited on a monthly basis, this doesn't mean that iOS apps will always wait for a Wi-Fi connection to transfer information.
There is a fix, which will limit which apps are allowed to connect using cellular data, and which apps are limited to Wi-Fi only. Here's how to configure apps to stop using up your mobile data plan:
1. Navigate to Settings -> Cellular
2. Scroll down to USE CELLULAR DATA FOR
3. Switch OFF (grey) apps to limit their bandwidth usage to Wi-Fi only
4. Apps with a green switch (ON) will continue to use cellular data and consume MB on your monthly data plan
Of course, to limit all apps from using cellular data you can set Settings -> Cellular -> Cellular Data OFF (grey switch). This will prevent the iPhone or iPad from using any cellular data, limiting all connections to Wi-Fi only.