Here's how to check your cellular data usage on an iPhone, and find specific readings for and manage each app's data.

I have an AT&T iPhone 4 with the 200 MB/month data plan. Last month, I somehow managed to exceed my monthly cap by 7 MB, even though the myAT&T app showed that I had used 180 MB with 5 days left in my ...

Most mobile carriers have a phone line for data usage checks. You can also see how much data is left in your online account or the company's app Data can cost you big bucks if you're not paying ...