With the advent of Apple allowing emulators into the app store, its finally time to get serious about retro gaming on the go. My fellow Android folks have had this luxery for over 15 years already.
This universal phone mount for the beautiful 8bitdo Lite 2 fits perfectly onto your phone of choice (Min: 70mm width, Max: 80mm)
For reference, here are some example phones and their widths:
Download the Delta emulator from the app store (or some other emulator) and get going!
I got my controller for about $29 from aliexpress here.