Originally published at: Keep Any iOS App Private with Biometric Authentication - TidBITS
As iPhones and iPads become an increasingly integral part of our daily lives, it’s not uncommon to have an app that contains information so personal that we wouldn’t want others to stumble across it. That could be a child using your iPhone to play a game or a friend swiping through photos you want to show them. To prevent unauthorized access, some apps containing personal data now offer options that require biometric authentication or a separate passcode before allowing access.
A new feature in iOS 18 and iPadOS 18 now enables you to protect any app with Face ID or Touch ID. It’s simple to set up and use: just touch and hold an app, then select Require Face ID from the menu that appears. The device will then prompt you to choose whether to require Face ID only or hide the app to prevent others from realizing it exists.
After enabling the option to require Face ID, your device will ask you to authenticate whenever you try to open the app or display its content in other places. With Face ID, you’ll barely have time to read “Face ID required to open App” on an otherwise blank screen before the app appears. With Touch ID devices, I assume you’ll need to move your finger to the Home or top button, which won’t be as seamless. If biometric authentication fails—like when Face ID doesn’t work for me because I’m not wearing my glasses and I hold the iPhone too close to my face—you must tap Try Face ID Again before trying to authenticate again. If multiple attempts fail, you’ll be asked for your passcode.
Hiding the app is more involved. When you tap Hide and Require Face ID, the device explains what will happen, although not very clearly. First, it says that the app “will no longer be visible on your iPhone, except in a few places such as Settings.” I’m unsure what other places Apple has in mind, but the apps I hid also vanished from Settings > Apps. Second, under “Obscured App Appearance,” Apple says that the app “will be obscured on your Home Screen and in a folder for hidden apps in the App Library.” This is just poor writing. The app isn’t “obscured” on your Home Screen; it disappears entirely from the Home Screen.
You could interpret the App Library’s behavior as “obscured,” though I wouldn’t describe it that way. A new Hidden folder appears at the bottom of your App Library but doesn’t display its contents until you tap it and authenticate with Face ID. Then, the icons of all the hidden apps appear, and tapping one opens it.
To turn off the feature, touch and hold the app icon on the Home Screen, in the App Library, or in Spotlight, and then choose Don’t Require Face ID from the menu that appears. If you want to reveal a previously hidden app but retain biometric authentication, you’ll have to toggle the entire feature off and back on.
Overall, Apple has done a commendable job of giving users more control over their privacy with specific apps. It’s important to remember that if you trust someone with your passcode, it could grant them access to your otherwise secure apps. However, it’s unlikely that anyone with passcode access would accidentally discover an app that’s hidden or even just restricted to the App Library. Security through obscurity is far from guaranteed, but it’s sufficient in many low-impact situations.
