GrendelPrime Software updates are help your device function at it's best. We apologize for the rebooting issue with the s3. Have you tried to power it off and remove the battery?
Follow us on Twitter
Hi GrendelPrime - I had the same issue on Saturday after the KitKat Update. During the update installation, my phone 'optimized' my 151 apps for the new KitKat OS. I think it stopped or froze during that process so that the optimization did not complete. Then I could only get back to the Verizon logo or Android Logo before it restarted.
I plugged my phone into my PC and downloaded the Repair Assistant mentioned in the Verizon update paperwork (if you just plug in your phone, it will begin the installation process on your PC - it's already on your phone). Once I had that application installed, I had to restart my phone while it was plugged into the PC in order for the application to see the phone. Then I noticed the optimization process picked back up (only had about 80+ apps to optimize). This took about 5-6 minutes then the phone rebooted and I had my home screen again!
I did have to restart my phone several times while it was pugged into my PC. Maybe it was that the installation process wasn't complete each time and it moved along in stages (like having to reboot your PC after each Windows update so it can download and install the next update).
I have tested ALL of my apps on my Galaxy S3 after the installation and have no issues (not even the battery or reception issues mentioned elsewhere).
Hope this helps -good luck!