Credit: Edgar Cervantes / Android AuthorityTL;DRAT&T has announced a Build-A-Plan option.This is a customizable carrier plan starting at $15 per month for unlimited talk/text and 1GB of mobile data.You can also pay extra to add more mobile and hotspot data for your next billing cycle.Finding the right cellular plan can be a tough challenge, but what if you could simply create your own plan? Well, AT&T has just announced Build-A-Plan, which it claims is a “fully customizable” wireless plan.AT&T Build-A-Plan has a base price of $15 per month and comes with unlimited talk, unlimited texting, and 1GB of mobile data. But the carrier will also let you add more mobile data and tethering data to your plan for the next cycle.