Tucked in the latest mandatory Sony PlayStation 4 system update (version 6.50) is support for PS4 Remote Play apps for iPhones and iPads.
With the apps, users can access their PS4 over Wi-Fi with an iPhone or iPad running iOS 12.1 or later. Using the on-screen controller you're able to control the console as well as display your PS4's screen on your device. Additionally, the app allows you to use your device's mic for voice chats and its keyboard for entering text.
Sony recommends using at least an iPhone 7, a sixth-gen iPad or a second-gen iPad Pro or later.
Remote Play was a key feature for the PS4 when it launched in 2013 via its PlayStation Vita handheld. The feature was then expanded to its Xperia phones the following year. In addition to the new iOS apps, it's available for Android, PC and Mac.