I actually used the same app to root my Verizon tablet (the Ellipsis 8). That thing was previously un-rootable. Anyway, to answer your question, the basics of rooting with this app is to go to the website
www.kingroot.net (it's in chinese) click on the big blue button. This takes you to the next page, click on the first blue download link for KingRoot. Go ahead and install that onto your device. Now from what I have heard, before you run the app seriously swamp your phone with running apps and processes. Then run the app and tap on the circle button. Eventually you will get a checkmark in the circle. The app will also install something called KingUser. This is more or less a replacement for SuperSU or any other Super User app. It IS in english and it works great.