Update Galaxy S3 I9300 with 4.1.2 Jelly Bam with Android 4.2 Apps Custom Firmware

• Last modified: Android Tips

You can now enjoy Android 4.2 on Galaxy S3 I9300 with this amazing new custom ROM, Jelly Bam which is based on Android 4.1.2 with Android 4.2 apps that have been leaked earlier before the launch of Nexus 4. It is a custom ROM for the Samsung Galaxy S3 I9300 with almost all the new apps of Android 4.2. We are still waiting for proper Android 4.2 AOSP custom ROMs to be out for Android phones. You can update Galaxy S3 I9300 to Jelly Bam 4.1.2 ROM with Android 4.2 Apps custom firmware using the tutorial below.

As you continue reading below, we will guide you through the entire process of how to install Jelly Bam 4.1.2 ROM with Android 4.2 Apps on Galaxy S3 I9300 with complete steps. Please make sure you backup all your data as given below because this tutorial will wipe your data. Remember, this is a custom ROM, not an official firmware update by Samsung. Let’s get to the tutorial now.

Samsung Galaxy S III GT-I9300

Disclaimer: All the tools, mods or ROMs mentioned below belong to their respective owners/developers. We (TeamAndroid.com) or the developers are not to be held responsible if you damage or brick your device. We don’t have you on gun point to try out this tutorial ;-)

Jelly Bam 4.1.2 ROM with Android 4.2 Apps Features:

  • - Built from source -
  • - Overall features of AOKP, CM10 and PARANOID -
  • - Custom JellyBam Settings with preferences -
  • - Tons of customizations -
  • - Themes and Mods in JellyBam style -
  • - Aroma installer -
  • - Latest CM10/AOKP vsync patched Kernel -
  • - Latest Siyah kernel -
  • - Google apps from android 4.2 -
  • - New Mali driver -
  • - Exynos HWComposer -
  • - Lockscreen with x8 Custom app targets -
  • - New optimus 4x circle lockscreen -
  • - Ability to customize color and alpha of the optimus lockscreen -
  • - Gallery, Camera and KeyBoard from 4.2 -
  • - Clock from android 4.2 -
  • - Google play music from android 4.2 -
  • - Sony Walkman music player -
  • - Bravia Engine libraries -
  • - Bravia XLoud audio libraries -
  • - Paranoid Android settings -
  • - Per-App-DPI Changer -
  • - Per-App-Color -
  • - Custom home action and hardware button in lockscreen -
  • - Quick/Long click on weather and clock actions -
  • - JellyBam Panel in settings app -
  • - Mass storage mode -
  • - OTA Update via UpdateMe App -
  • - You can keep your ROM up to date with latest Tweaks, Mods, Themes via UpdateMe app -
  • - GAPPS included, no need to flash anything else -
  • - Gallery support picasa share -
  • - Apollo Music Player (Themed) -
  • - Album app from sony xperia -
  • - Quick SMS -
  • - AwesomBeats Lib -
  • - A good combination of stability and performance (Thanks Siyah Kernel + Personal mod) -
  • - Bluetooth hacked for send / receive APK -
  • - YouTube hacked with 3G+WiFi HD 720p PlayBack -
  • - Init.d scripts -
  • - JellyBOOM script -
  • - Media quality tweak -
  • - 3G and GPS Tweak -
  • - RAM Optimization + Multitasking -
  • - SmoothScrolling tweak -
  • - V6 Supercharger included -
  • - lot of Themes available in UpdateMe -
  • - TouchWiz 5 Launcher -
  • - Apex and Launcher Home-
  • - AC!D Technology (Thanks to r-ikfoot) -
  • -*Beats Audio by Dr Dre*(Powerfull bass) -
  • - Clearbass Sound by Sony*(Clear Bass) -
  • - Xloud by SonyEricsson*(higher sound volume and clearer sound on speaker) -
  • - Dolby Digital Sound*(Equalizer enhancer bass setting and Surround setting) -
  • - Surround Sound*(Deeper bass and reduction of bass distortion plus Eq setting support) -
  • - JellyBam custom Bootanimation -
  • - Center Clock/No clock/Right Clock -
  • -Volume Panel (Volume Rocker allows you to change ALL volume levels in one Menu) -
  • - Lockscreen Weather -
  • - Lockscreen Vibration on/off toggle -
  • - Performance/Color Settings -
  • - Brightness Control Slider -
  • - Multilang -
  • - JellyBam Style -

Make sure you have installed all your USB drivers for the Samsung Galaxy S III to connect it with the computer. Download Samsung Galaxy S3 USB drivers! Apart from just the USB drivers, there are a few more things that you need to take care of.

1. You need to enable USB debugging mode. This helps to connect your Android phone with the PC. See here: How to Enable USB Debugging.

2. Your phone battery should be 80-85% charged. If your phone goes off suddenly because of battery, during flashing ROMs or installing mods and updates — your phone might go dead permanently. See here: How to Check Battery Percentage.

3. Backup all your important data that you might need as soon as your flash a new ROM, or make a backup for just in case, you never know when anything might go wrong. See below on how to backup data:

Data can also be backed up using Samsung KIES for their devices, but if you backup data manually, you get more options what top choose from and it is very easy to move data across Android devices from different manufacturers, i.e moving Samsung Galaxy Note backup data to HTC One X.

4. Your phone should be factory unlocked. Additional instructions for locked Android devices will be added in the tutorial for unlocking devices.

Now, let’s proceed with the tutorial on the next page and update Galaxy S3 I9300 to Jelly Bam 4.1.2 ROM with Android 4.2 Apps custom firmware.


  • Jefferson Gonzales

    why can’t I update? e:/signature verification failed always comes out… please reply… thank you

    • Jeff

      because you did something wrong

      • Jefferson Gonzales

        what would be wrong? please help… thanks…

  • yf

    is there hebrew language support? native to 4.1.2? instaled 4.1.1 and there’s arabic but oddly no hebrew.

  • Bella

    I was on Turkbey Custom Rom for quite some time and I found out about this JellyBam. Backup my phone with TB as usual. Installed JellyBam but most of the features mentioned above are not available on my phone.