Owners of the AT&T Galaxy S3, rejoice! The first custom ROM for the newly released device is out, called Ultimatum ROM and released by XDA Senior Member howtomen. Ultimatum ROM primarily removes much of the bloatware/unnecessary Samsung made apps that come preloaded on the device, with a few other features such as the ability to have a scrolling wallpaper in the default launcher aka TouchWiz.

Here are the main features of the ROM:

  • Very Debloated, Removed S Voice and other Samsung apps
  • Advanced Reboot menu
  • Scrolling Wallpaper on TW launcher
  • Modified MMS to allow fonts, Enabled various MMS options
  • Removed Boot sound

This is just the beginning and we’re sure the future will bring many more improvements and features, but for now, let’s take a look at how Ultimatum ROM can be installed on your AT&T Galaxy S3.

Compatibility

This guide below is compatible only and only with the AT&T Galaxy S3. It’s not compatible with any other Galaxy S3, it only works for AT&T variant. Check your device’s model in Settings» About phone.

Warning!

The methods and procedures discussed here are considered risky and you should not attempt anything if you don’t know completely what it is. If any damage occurs to your device, we won’t be held liable.

How to Install Ultimatum ROM on AT&T Galaxy S3

  1. This procedure will wipe all your apps, data and settings (but it will NOT touch your SD cards, so don’t worry about those). Backup your Apps and important data — bookmarks, contacts, SMS, APNs (internet settings), etc. This Android backup guide would help you.
    Important! Don’t forget to at least make a backup of your APN settings, which you can restore later if your data connection does not work after installing the ROM. Use the backup guide to find out how.
  2. Install ClockworkMod recovery on your phone by following the guide → here.
  3. Download the latest version of the ROM from the official development page.
  4. Transfer the downloaded zip file from step 4 to the internal SD card on the phone.
  5. Now, boot into ClockworkMod recovery. To do that, turn off your phone. Then, hold down Volume Up, Home and then the Power buttons together until the screen turns on, then let them go. The phone will boot into ClockworkMod recovery in a few seconds.
    In recovery, use the volume buttons to scroll up/down and the home button to select an option.
  6. Perform a Nandroid Backup of your existing ROM, so that you can always restore it from recovery if something does not work out with this ROM. To perform a backup, select Backup and Restore –> On the next screen, select Backup again, then wait for the backup to finish. Go back to main recovery menu after backup is complete. Keep in mind that at least 1 GB of space is required on the internal SD to make a successful backup.
  7. Select wipe data/factory reset, then select Yes on next screen to confirm. Wait a while till the data wipe is complete.
  8. Select install zip from sdcard, then select choose zip from sdcard. Scroll to the ROM file on the SD card and select it. Confirm installation by selecting Yes – Install _____.zip on the next screen. The ROM will start installing.
  9. After the ROM finishes installing, select go back then select reboot system now to reboot the phone.

Ultimatum ROM is now installed on your AT&T Galaxy S3. Visit the official development page to get more info and to get the latest updates on the ROM. Share your thoughts on the ROM in the comments below.