Privacy Policy — Last updated: September 9, 2026
Formulary does not collect any personal information. NO DATA
Formulary offers optional paid upgrades (Formulary Pro), processed entirely through Apple's App Store / StoreKit 2. We never handle, receive, or store any payment, card, or billing information.
Subscriptions renew automatically unless cancelled at least 24 hours before the end of the current period. You can manage or cancel a subscription at any time in your Apple ID Account Settings; we have no ability to do so on your behalf and receive no notice of your billing activity beyond your entitlement status.
Entitlement status (whether Pro is active) is determined on-device from the StoreKit 2 transaction signed by Apple. It is stored only on your device and is never sent to us or to any third party.
Purchase records are held by Apple and restored via your Apple ID. We keep no independent copy.
Apple's Privacy Policy governs all transactions: apple.com/legal/privacy
Terms of Use (EULA): Apple Standard EULA
Formulary does not use any third-party analytics SDKs (no Firebase, Mixpanel, Amplitude, etc.).
App Store Connect may provide Apple's standard aggregated, anonymous analytics from users who have opted in. We cannot identify individual users from this data.
The app uses the internet only to render LaTeX formulas via the KaTeX library (loaded from
cdn.jsdelivr.net). Formula content is bundled locally.
No user data is transmitted over this connection. As with any web request, the CDN receives your device's IP address and standard request headers; this is handled by jsDelivr and is not collected, logged, or seen by us.
Formulary is suitable for all ages. Since we collect no personal data from any user, there is no specific data handling concern for any age group, including children under 13.
| Service | Purpose | Notes |
|---|---|---|
| KaTeX (Khan Academy) | LaTeX rendering | MIT license — no user data sent |
CDN:
https://cdn.jsdelivr.net/npm/katex@0.16.9/
All app data is stored locally on your device and protected by iOS's standard encryption and sandboxing. We have no access to this data.
Because we collect no personal data, we have nothing to retain. Everything the app stores — favorites, notes, solver history, settings — lives only in the app's on-device SwiftData database.
Deleting Formulary from your device permanently deletes all of it. Purchase and subscription records are kept by Apple under Apple's own retention policy, not ours.
Privacy laws such as the GDPR (EEA/UK) and CCPA/CPRA (California) give you rights to access, correct, export, delete, and restrict the processing of your personal data, and to object to its sale.
We do not collect, process, store, sell, or share any personal data, so there is no data held by us for these rights to be exercised against. You already hold the only copy of your app data on your device, and you can delete it at any time by deleting the app.
For data connected to your purchases or your Apple ID, contact Apple directly at privacy.apple.com. If you have any question about this policy or believe we hold data about you, email us and we will respond within 30 days.
If we make changes, we will update the "Last updated" date at the top of this page.