King root is a rooting app developed by xda forums.It basically reduces work of connecting to PC and rooting by providing one touch root operation, its a nice app provided with some bugs to be fixed.The app basically breaks the security of the smartphone but this app has some issues too as this app helps to root to the older devices say Android version less than marshmallow.
This app is not available in play store or AppStore and has to be downloaded by simply googling king root app and has to download in xdaforums website. Please note that this app fails to root the latest devices as the latest devices comes with more developed kernel version and security so don’t try to root your precious smartphone with this app if you use latest device.