Hey guys, tried rooting phone and now it wont load past startup screen.

I'm on a galaxy s4, not sure what OS it was. I downloaded an app named King something to root my phone. After a system update it now fails to boot past the "samsung" opening screen. I would like to get access to my phone back, even if it means flashing it. Any and all advice is much appreciated. thank you

from xda-developers http://ift.tt/1rxCsVn
via IFTTT