Works for OnyxCalc whether or not it has its own passcode. No download needed.
Touch and hold OnyxCalc's icon, tap Require Face ID, then confirm. On iOS 18 and later that puts OnyxCalc behind Face ID, Touch ID or your passcode; choose Hide and Require Face ID instead to move it into App Library's Hidden folder as well.
Lock OnyxCalc with Face ID
- Find OnyxCalc on your Home Screen or in App Library.
- Touch and hold the icon until the quick-actions menu opens.
- Tap Require Face ID (or Require Touch ID / Require Passcode, depending on your iPhone).
- Tap Require Face ID again to confirm. OnyxCalc now asks for authentication every time it opens.
To test it, close OnyxCalc from the App Switcher and open it again. You should see the Face ID prompt before any content appears.
Hide OnyxCalc in App Library
- Touch and hold OnyxCalc's icon and tap Require Face ID.
- Choose Hide and Require Face ID instead of Require Face ID.
- Confirm. The icon leaves your Home Screen and moves to the Hidden folder at the bottom of App Library.
- To open it later, swipe to App Library, tap Hidden and authenticate.
Hiding also locks the app. To undo either, touch and hold the icon again and choose Don't Require Face ID.
Why lock OnyxCalc?
OnyxCalc's privacy label lists user content — the kind of data you would not want on screen if someone borrows your unlocked phone. Private-photo apps promise to keep pictures out of your main library. The label shows what leaves the phone; it cannot show whether the hiding is a real lock or just a separate folder.
Utilities range from calculators to VPNs, so their labels vary more than any other category. A simple tool that collects identifiers and usage data for tracking is a sign of advertising SDKs.
A lock answers one question — who can open the app on this iPhone. It does not change what OnyxCalc sends to its developer; for that, see OnyxCalc's full privacy report.
What the lock does and does not do
It does
- Ask for Face ID, Touch ID or passcode every time OnyxCalc opens
- Hide message previews in notifications
- Keep OnyxCalc's content out of Spotlight and Siri suggestions
- With Hide, remove the icon from the Home Screen
It does not
- Stop someone who knows your passcode
- Encrypt or change how OnyxCalc stores data
- Sync to your iPad or other devices
- Remove OnyxCalc from purchase history or Screen Time reports
Don't see Require Face ID?
- Update to iOS 18 or later in Settings › General › Software Update.
- Make sure a passcode is set in Settings › Face ID & Passcode; the lock needs one.
- Some Apple apps (Settings, Calculator, Camera, Maps, Find My, Clock) cannot be locked or hidden.
- If your iPhone is managed by work or school, the option may be restricted.
Other settings worth checking for OnyxCalc
Tracking
Settings › Privacy & Security › Tracking. If “Allow Apps to Request to Track” is off, apps cannot ask, and they are told to treat you as having declined. You can also turn it off for this app alone.
Photos
Settings › Privacy & Security › Photos. Limited Access lets you pick exactly which pictures the app can see; Add Photos Only lets it save without reading your library.
Notifications
Settings › Notifications › OnyxCalc › Show Previews: When Unlocked keeps message and account details off the Lock Screen.
OnyxCalc's full privacy label
None declared
None declared
Lock these apps too
After you lock OnyxCalc
Done. You have applied every control the label points to.
FAQ
Does OnyxCalc have its own passcode?
What happens to OnyxCalc's notifications when it is locked?
Can someone who knows my passcode open a locked app?
Is a locked OnyxCalc encrypted?
Why can't I see the Require Face ID option?
Does hiding OnyxCalc remove it from my purchase history?
Is OnyxCalc safe? Full privacy report →Does OnyxCalc track you? →Lock an app: A–Z →All utilities apps →