First we'll cover setting up the plan on your iPhone, then cover tips to help keep your data and minutes down to a reasonable amount. To start, you need an AT&T or unlocked iPhone.
By default, iPhones are not configured to use the GoPhone data proxy. In the next few steps we will update the carrier settings so you can use an AT&T pre-paid data plan on iPhone.
Now we'll configure your GoPhone account with a data plan and add some credits for calling.
You'll be asked to enter a credit card to pay for the data plan. Your account balance should be at zero now.
Keeping Calls & Data Costs Under Control
And that's about it. Let me know in the comments how it works out for you!