Principia is designed to stay calm and understandable, including when something needs attention. These steps cover the most common questions.
Revealing today’s equation
On the Today tab, press and hold the main card for about one second. The card responds as you hold, then opens into the equation and its story. VoiceOver users can activate the reveal control without relying on a visual gesture.
Principia presents one new equation each day. If today’s equation was already revealed on this device or another synced device, opening it again is a quiet reread and does not count as a new reveal.
Principia Pro purchases and access
Open Settings > Restore Purchases to recover an active subscription or Lifetime purchase made with the same Apple Account. You can also restore from the purchase screen.
If a completed purchase is still being verified, use Check Again when it appears. StoreKit may continue working after a slow connection. If the App Store operation never finishes, close and reopen Principia before trying another purchase or restore.
Manage or cancel an active subscription from Settings > Manage Subscription in Principia, or through your Apple Account subscriptions. Deleting Principia does not cancel a subscription.
Private iCloud sync
Reveal history, favorites, daily selections, and quiz progress can sync through your private iCloud database when iCloud is available. Use the same Apple Account on each device and allow a moment with Principia open for changes to arrive.
We cannot see or recover data stored in your private iCloud database. To remove supported synced progress, use Settings > Delete Synced Data. The retained free-reveal allowance is handled separately, as explained in the Privacy Policy.
Reminders and widgets
Daily reminders, streak nudges, and eligible trial-ending reminders are scheduled locally on your iPhone. Adjust the daily reminder in Principia Settings and notification permission in iOS Settings.
Home Screen and Lock Screen widgets refresh from locally shared app data. If a widget looks stale, open Principia once, then return to the Home Screen or Lock Screen.
Privacy and data
Principia has no advertising, tracking, or third-party analytics SDK. Optional feedback is the only content you deliberately send to us from inside the app. Read the complete App Privacy Policy for the data flow, retention, and deletion details.
Still need help?
Email joinprincipia@gmail.com. Include your Principia version, iOS version, what you expected, and what happened. Please do not send passwords, payment details, or sensitive personal information.