Update: to block the 4.4 Kit Kat update follow the information below but use the build # L710VPUCNJ3 instead of L710VPUBMK5. I figured there are others like me avoiding the MK5 4.3 update so I thought I would post how to stop that annoying notification once and for all. There are other methods that say to freeze this app or rename this file but both those methods mess up other things. The correct way is to modify your build.prop. The following instructions are how to modify the build.prop manually but there also are build.prop editors you can use. However I've never really messed with any so i won't be able to provide much help if you have a problem. If you use a build.prop editor then you only need to look at steps 1, 4, 5 & 6. Please make a backup with a custom recovery first. I am not responsible if you brick or damage your phone! I have done this mod successfully on my phone and my old phone when I wanted to block it's OTA. I can't stress enough how important it is to make a backup before modifying /system! While there are quite a few steps listed below this is a pretty simple process. Basically all you need to do is copy a file, edit 2 words (sort of), rename the old file (to create a backup), then replace it with the new edited version. 1. Boot into recovery and make a backup! This is very very important even if you are using a build.prop editor. If you modify your build.prop incorrectly you could end up stuck in a boot loop. After you make a backup restart back into Android. 2. Using your favorite root explorer (I use ES File Explorer) navigate to /system and copy your build.prop to your sdcard. 3. Open the build.prop in a text editor (I use the one built into ES File Explorer.) 4. Scroll down 10 lines or so. What you're looking for is the 2 lines after: I find it easier to look for that line. 5. The 2 lines you need to edit are one right after the other: 6. Next replace L710VPAMG2 with L710VPUBMK5 in both lines. When you're done it should look like this: 7. Make sure system is mounted as writable. 8. Navigate back to /system. 9. Rename your old build.prop found in this directory to build.prop.bak (it's always good to have backup!) 10. Copy your newly modified build.prop to /system 11. Check the permissions for your new build.prop. I had to add the read permission for group and other (it should be 644). 12. Navigate to /cache and delete the OTA update. It should be a zip file with a real long file name. The file name for me ended with MG2_to_MK5_Update_FWD.zip. On my S3 it was the only zip file in that directory. 13. Make sure system is no longer mounted as writable. 14. Reboot your phone. After first boot if the OTA notification is still present just swipe it away from the notification shade (don't click on it.) And that's it. I haven't had any update notification for 2 days now. This should work with any rom (and any carrier) but if you're running a Sprint rom the build # you're changing may look different. Also if you have a custom rom there may already be a flashable zip to fix your build.prop. Moar & Wicked Sensations both have zips. One other thing. Only change the build # in the 2 lines that are posted above. Changing Android version numbers or the build # in other places could cause unwanted results. For example, if you go to settings, about phone, you'll notice it still says MG2 after this fix. But Boost thinks you're on MK5. Enjoy!