Many iPhone users have trouble keeping an eye on their data usage. iOS 8 has a built in feature to help you do just that.
Go to Settings > Cellular and scroll down to Use Cellular Data For
Next you'll see an alphabetical list of every app on your iPhone. For each app you'll see an option to enable the use of cellular data by toggling the button to the right. If you toggle an app off you'll still be able to use the app it just means that the app won't update if you're not connected to WiFi.
Underneath each apps name you'll see the amount of data the app has used during a certain period of time.
If you scroll all the way down you'll see that your iPhone keeps track of all cellular usage during that certain period of time.
If you like you can reset the data just tap Reset Statistics.
This is a great feature to use if you have apps that eating up your data.
Go to Settings > Cellular and scroll down to Use Cellular Data For
Next you'll see an alphabetical list of every app on your iPhone. For each app you'll see an option to enable the use of cellular data by toggling the button to the right. If you toggle an app off you'll still be able to use the app it just means that the app won't update if you're not connected to WiFi.
Underneath each apps name you'll see the amount of data the app has used during a certain period of time.
If you scroll all the way down you'll see that your iPhone keeps track of all cellular usage during that certain period of time.
If you like you can reset the data just tap Reset Statistics.
This is a great feature to use if you have apps that eating up your data.