How to create android apps with root access?

Question

I found out that there\'s so many apps out there which required root access.

How were they able to create those apps? Where did they found all the resource? Is ther

Answer 1

Usually rooted apps are just using commands like "su ...", which they aren't able to use without root access. And with these command executions can they reach everything (i.e. removing a system app or boosting your android device)