We'll help solve this data mystery! There's actually a lot of things on a smartphone that can contribute to data usage. Did the unexpected usage begin when you first got your iPhone? Or possibly after installing a particular application? On an iPhone, you may be able to determine where most of the data is coming from by going to Settings>Cellular and scrolling down to the list of applications and their use. This will help you determine what programs have been adding to your usage and even give you the option to turn cellular data off for individual applications so they only use WiFi. Make sure you're connecting to WiFi whenever possible to help conserve. Also, close applications when you're done using them by double tapping your home button and swiping applications up and off the screen.
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