Android customizations are getting better each day and at the core of this is the continuous development of new custom ROMs. Some developers want to build a ROM for the masses, while others just want to build their own ROMs for their personal use. XDA Developers member leamoor, however, doesn't want to keep the Supreme ROM a secret.

The Supreme ROM is based on Android 4.1.2 build XXELKC and has the stock look but with a lot of modifications and tweaks. It's smooth, stable and most importantly, “really fast” according to its developer. It comes with Multi Window with a transparent background, a transparent notifications menu, 75% transparent homescreen status bar, a blue center clock, and an original bootup and shutdown animation.

Of course, there's more to the Supreme ROM than just aesthetic tweaks. The ROM's been rooted with SuperSU and binary, deodexed and zipaligned, and comes with bash and nano cross-compilation, sysrw and sysro binaries, a sysctl.conf tweak, improved RAM management, and faster application loading times.

This guide shows you how to flash Supreme ROM for the Galaxy S3 LTE I9305.

Warning

• The instructions in this guide are intended for use with the Samsung Galaxy S3 LTE, model number GT-I9305. Applying these instructions on another device or model may produce undesired outcomes.
• The information in this guide is provided for instructional and educational purposes only. There is no guarantee that these instructions will work under your specific and unique circumstances.
• Use these instructions at your own risk. We shall not hold any responsibility or liability for whatever happens to you or your device arising from your use of the info in this guide.
• Read and understand the whole guide first before actually performing the instructions.

Requirements

• Samsung Galaxy S3 LTE, model number GT-I9305 with root access and ClockworkMod Recovery.
• Download the Supreme ROM 5.0 (supreme_rom_5.0.zip, 696 MB) to your computer.
• Make sure your phone's battery still has at least 70% power. You don't want the device to shut down in the middle of the procedure.
• Backup all personal data on your phone to make sure you have a copy of your personal data (e.g., contacts, SMS, MMS, Internet settings, Wi-Fi passwords, and the like) in case the procedure in this guide erases such data.
  • For backup tips, check our guides on how to sync your data to the cloud and how to create local backups of your mobile data.

Instructions

1. Copy the Supreme ROM file to your phone's internal SD card.
2. Turn off your phone.
3. Put it in Recovery Mode by holding the Volume Up, Home, and Power buttons together until you see the Samsung Galaxy S III text on the screen.
   • NOTE: while in Recovery Mode, use the Volume Buttons to navigate and the Power button to select options
4. Make a NANDroid Backup. Go to Backup and Restore > Backup.
5. Do a full data wipe. If you current ROM is Supreme ROM 4.0, you don't need to wipe anything.
   • Select Wipe Data/Factory reset and confirm by selecting Yes.
   • Select Wipe Cache Partition and confirm by selecting Yes.
   • Select Advanced > Wipe Dalvik cache and confirm by selecting Yes.
6. Select Install ZIP from SD card > Choose ZIP from SD card and select the Supreme ROM file.
7. Go back to the main menu and select Reboot system now.

Great! You've just installed the Supreme ROM to the Samsung Galaxy S3 LTE GT-I9305.