Making use of the Voucher_Swap exploit, CarrierChanger12 provides anyone ruuning a 16k device on iOS12-12.1.2 to change their carrier logo to any text at the press of a button.
How to use: Open the app, enter the custom carrier, click “Apply”, please wait patiently for the file generation and it pop-up prompt, click “Okay”, and click “Reboot” to restart the device. If you want to restore the original carrier icon, click "Restore With Backup" and wait for the restart.