T-Mobile My Account is the easiest and fastest way to connect with T-Mobile on your phone. From one easy to use application, you can view and manage your T-Mobile account, quickly access Help and How-to’s for your phone, receive customized notifications, and learn more about T-Mobile services. You can also set alerts and reminders to help you optimize your phone’s battery and performance. This is a FREE service; there are no usage charges (including data) to use the application or view account usage information.
PLAN USAGE MAY DISPLAY IN THE NOTIFICATION BAR
After installing the application, your plan’s usage information will be updated once per day and display in your phone’s notification bar. The T-Mobile My Account icon will also display in your phone’s status bar until this feature is disabled. This feature is not available on all account
types.
*** IMPORTANT ***
To disable this feature, open the T-Mobile My Account app and select Menu > Options or deselect the check box loca

Optimize battery performance.