"Going Zero Controller" is a controller iOS app which control Mac app called "Going Zero for Mac" via Wi-Fi network.
You need Mac and "Going Zero for Mac" installed on you Mac.
Then connect your Mac and iPhone/iPad on same Wifi network.
Going Zero for Mac is available at:
https://kyab.github.io/Going-Zero/
Check Going Zero Controller working in action:
https://youtu.be/KmAr8PCVP08