To unhide an app on your iPhone running iOS 18 or later, follow these steps:

1. From the Home Screen, swipe left until you reach the App Library.
2. Scroll down to the bottom and tap on the Hidden folder.
3. Authenticate using Face ID, Touch ID, or your passcode to access the hidden apps.
4. Find the app you want to unhide, then long-press (tap and hold) its icon.
5. In the menu that appears, select Don't Require Face ID (or Touch ID/Passcode, depending on your settings).
6. Authenticate again if prompted. This will remove the app from the Hidden folder and return it to the regular App Library.
7. Optionally, if you want the app back on your Home Screen, long-press the app icon again and select Add to Home Screen.

This process effectively unhides the app and restores it to your visible app collection