For a long time, you were able to use a Windows desktop or Android device (as long as it's a Sony), but today the PS4 Remote Play app is hitting iOS devices. You'll be able to use an iPhone or iPad as a PS4 display over Wi-Fi. PS4 Remote Play on a Sony tablet You'll also be able to use an on-screen gamepad to control your PS4. Voice chat in supported games are also supported on the app so you can use the iPhone's microphone. You'll also be able to use an iOS device for keyboard input. The app will work with any iOS device running version 12.1 or later. Sony recommends an iPhone...
Source: https://www.gsmarena.com/ps4_remote_play_app_now_available_on_ios-news-35907.php
