IPhone : Is there a way to emulate a click (or finger touch) on an iPhone/iPad?

This is my first question here so I hope I do it right.

I'm starting to learn Swift right now and I want to know, is there a function/way to emulate a person touching (clicking) the iPhone/iPad screen? It doesn't matter where, it could be coordinates 0,0 or 100,100 or anywhere else in the screen. I just need to know if such function or whatever exists, and if it can be done, would be be considered legal to use in an app submitted to the App Store?

Thanks in advance for your help!