How to make a "click" on the smartphone screen through arduino?

Question

Arduino

I want to write a bot for one game (only for the purpose of self-development). Of course, you need to “click” on the smartphone screen, I immediately planned to do it with a servo, but then I came across this video: https://www.youtube.com/watch?v=dJW59UliLhc In it, a contact is attached to the screen that sends something to screen when the relay closes.
Question: what is being contacted? Earth from the arduino itself?
PS I have an iPhone 5s maybe this is important.

Answer 1

A coin is taped to the screen. Here is the description of the project and the program code . And here is an article on Habré .