If your wireless carrier preset this app for you, its usage measurements should reset at the end of every billing cycle otherwise, you'll have to adjust those times yourself. In current versions of Windows Phone, open 'Data Sense' from the apps list. This resets once a month, and you can ask this app to limit your usage and warn you when you near that cap. In Android, open the 'Settings' app and select 'Data usage' (or, on most phones, swipe down with two fingers to bring up the 'Quick Settings' panel, then tap the icon for your wireless carrier's signal strength).

The data-usage gauges in Android and Windows Phone don't suffer from either of those problems.

This accounting doesn't reset with each billing cycle or at other automatic intervals, so you need to remember to do that: Swipe all the way down and tap 'Reset Statistics.'.

Apple lists your apps alphabetically instead of in descending order of their data usage, the way you'd expect.

Two issues make these measurements less useful than they could be: You can block any one app from your mobile broadband and confine it to Wi-Fi alone by tapping the green slider control to its right. The figures in this report may surprise you app updates, for example, can gobble up a strikingly high amount of bandwidth.

Reset statistics on iphone