Much like PACman, XDA developer Johnhany97 has developed the custom firmware for T-Mobile Galaxy S4 named ReVolt custom ROM. ReVolt for T-mobile Galaxy S4 is a combination of CyanogenMod, AOKP and Paranoid Android. Many features like per-app-DPI, per-app-color, Power widget, option to select saving location in camera, option to control cursor in text fields using volume keys, and interesting multi user option are to name just a few.

Pre-reqs to update Galaxy S4 to ReVolt Android 4.2.2 Custom ROM:

Create a backup of all important data in your Galaxy device.Download and install USB drivers for Galaxy S4 in your computer.Enable USB debugging option by pressingMenu>Settings>Applications. Navigate and tap onDeveloper Optionsto ensure thatUSB Debuggingis enabled.Make sure thatClockworkMod recoveryorTWRPis installed.Ensure that your SGS4 carries more than 70% of charge.

How to update Galaxy S4 to ReVolt Android 4.2.2 Custom ROM:

Required files: download the ReVolt for T-Mobile fromhereand alsodownload the Google Apps Package fromthis link.

Connect your Galaxy S4 with the computer using the USB data cable and copy the files on your Galaxy S4.Disconnect T-Mobile Galaxy S4 from the computer and switch it off to boot it into the recovery mode:press and hold thevolume up,homeandpowerbuttonssimultaneously - release when the Samsung logo shows up.From the recovery mode menu, wipe data: selectwipe data/factory resetoption and confirm the operation. Clear thewipe cache partitionand thenwipe dalvik cacheto clear dalvik too.

Flash the firmware file now: selectinstall zip from sdcardfollowed bychoose zip from the sdcardoption.Locate the ReVolt ROM file for T-Mobile Galaxy S4 and confirm installation.Once installation is completed successfully, repeat the above step and install the Google Apps package file.Once done, go back to main menu andselectreboot system nowto boot your T-Mobile Samsung Galaxy S4 to the newly flashed ReVolt custom ROM. First boot takes some time, so be patient.

Ta da! Your T-Mobile Galaxy S4 is now running the ReVolt custom ROM loaded with amazing features!