Normally, you dont have to do anything. For ATT, hosting a Hotspot counts as the same as using any other app. Thats, because they only see that your phone is connected to their radio mast and what you are transfering, but not wich apps are using this connection.
XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality. Are you a developer?