If you are still using Samsung Galaxy S3 you can try to update your current version to the latest android version.Galaxy S3 I9300 can be updated to the latest Android 7.1 Nougat.
Although its not release by Samsung official its a custom rom.
ResurrectionRemix custom firmware has develop the update for Galaxy S3 I9300.Android 7.1.1 Nougat, the beta ROM will enhance the device performance and it come with some amazing features, including all CM14.1.
-Navbar Button Customization smartbar
-Double Tap To sleep navbar
-Enable/Disable Show Notification Count
-Battery Bar customization
-Battery Icon Customization(circle/landscape/Potrait and more)
-Battery % Text
-Power Menu Animations
-Gestures Anywhere Feature
-3 Finger Swipe Screenshot Gesture
-App Circle Bar
-Choose apps in AppSidebar
-Choose apps in App circle
-Pie Trigger(left ,Right ,Bottom)
-More Pie Features
-Clear All button Switch
-Clear All Tasks Switch
-Clear All Button Location(Top right,Top Left,Top Center,Bottom Left,Bottom Right,Bottom Center)
-Full Screen Recents
-Lockscreen Bottom Shortcuts
-Lockscreen General Shorcuts
-100+ Icons for Shortcuts
-Double Tap to Sleep Lockscreen
-Lockscreen Media Art/Enable Disable
-Quick PIN/Patter Unlock
-Lockscreen Weather Widget
-Lockscreen Icons Color
-Quick Settings Draggable Tiles
-Dyanamic Tiles Adjustment
-Number of columns/rows
-LongPress Toogles to Enter Settings
-Disable Immersive Mode Messages
-Force Expand Notification
-Notification Panel Transperency
-Volume Dialog Transperency
-Notification Panel Stroke
-Volume Dialog Stroke
-Advanced Reboot Menu
-Power Menu Customizations
-Reboot(Recovery, Bootloader, Hot Reboot)
-Power Menu End Calls Switch
-On the Go Mode
-Home Button(For devices with HW keys Only)
-Home Button answer call
-Long Press Actions
-Double Tap Actions
-Menu Button(For devices with HW keys Only)
-Short Press Actions
-Long Press Actions
-Search Button(If Device Supports)
-Short Press Action
-Long Press Action
-Wake Up Device
-Ringtone Volume Control
-Keyboard Cursor Control
-Swap Buttons on Landscape mode
-Volume Key Answer
-Enabled By default
-Removed Demo mode and Tweaked SystemUI Tuner As compared To AOSP
-StatusBar Icons Cuzomizations
-Quick Settings Customizations
-Expanded Desktop Mode
-Heads Up Switch and customizations
-Configurable 0,90,180,270 Degree Rotation
-Lock Screen Autorotate Switch
-Native Tap to Wake From Marshmallow
-Double Tap Power Button To enable Camera gesture
-Prevent Accidental Wakeup
-Wake Phone on Charging Plug
-Battery Light Customizations
-Notification Light Customizations
-CM privacy guard
-Performance Tweaks(Kernel Aduitor Inbuilt)
CM root inbuilt
-OverAll Smoothness Improvements
-Optimizations to Improve Battery
-Includes All Android Nougat Features
-Includes ALL CM14.1 Features
Before you want to install the updates on your handset it needs to have at least 80 percent remaining battery power for the firmware update.
Take a backup of your phone Reboot into custom recovery mode as
a complete wipe will be required during the flashing process.
Perform A Full Wipe data factory reset Install Rom from SD Card .
You can download the Android 7.1.0 Nougat based ROM from here.
Enable USB debugging option on your device: Settings > Development Options > USB debugging.
Samsung Galaxy S3 must be rooted, unlocked and installed with a recovery tool like TWRP.
Step 2 – Connect and mount your Galaxy S3 USB memory on your computer using the USB cable.
Step 3 – Now copy/paste the downloaded Android 7.1 ROM zip and Google Apps zip files to your SD card. Make sure the files are in the SD card root (not in any folder).
Step 4 – Then turn OFF your phone and disconnect from the USB cable.
Step 5 – Now to get in the Recovery Mode. Switch ON the phone while pressing and holding Volume Up + Home + Power buttons together
NOTE: Screenshots of the ClockworkMod Recovery may change as new versions are released.
Step 6 – Once you are in ClockworkMod Recovery, select perform a full data wipe by selecting “wipe data/factory reset” as shown below. Use the Power button to select everything while in the Recovery Mode.
Step 7 – Then, perform a cache wipe by selecting “wipe cache partition” as you can see in the image below.
Step 8 – Now this is optional, but it is recommended to perform a wipe of your dalvik cache as well. You will not get into boot loops or any other errors. From CWM recovery, go to ‘advanced’ and then select “wipe dalvik cache”.
Step 9 – Then go back to the main recovery screen and select “install zip from SD card”.
Step 10 – Now select “choose zip from sdcard”. Using your volume keys, navigate to the Android 7.1 ROM zip file that you copied to your SD card and select it using the Power button. Confirm the installation on the next screen and the installation procedure should start now.
Google Apps: Repeat the above step for the Gapps zip file as well and install it on your phone.
Step 11 – After the installation completes, go to “+++++Go Back+++++” and reboot the phone by selecting “reboot system now” from the recovery menu as show below.
Your Galaxy S3 I9300 will boot now and it might take about 5 minutes to boot on your first time. So, please wait.Galaxy S3 should now have ResurrectionRemix Android 7.1 Nougat custom ROM installed on your phone!