Tracking and managing cellular usage in iOS Settings
Apple includes a fairly detailed view for cellular usage within iOS settings and even includes the ability to see how much cellular data has been used by individual apps.
1. Open your iPhone settings.
2. Click on the section that says "Cellular."
3. On this screen, you will see a section that says "Current Period."
4. The number to the right of "Current Period" shows how much data you've used. Below this, you'll see various apps with a number below them. This indicates how much data you've used on each app. You can also turn off the green button next to each app to prevent an app from using cellular data.
5. If you're unsure what your "Current Period" is, scroll all the way to the bottom of this screen.
6. Here, below "Reset Statistics," you will see the term "Last Reset" with a date. Your "Current Period" data usage number begins with this date.
7. If you're trying to measure your data usage in relation to your cellular billing cycle, you can click "Reset Statistics," which will reset the "Current Period" of your data usage.
8. Click "Reset Statistics" again when it pops up, and you're all set!