Privacy, expressed plainly.

Who we are

Principia is made by Taton David and operated from Saint Lucia. Where privacy laws apply, Taton David is the controller responsible for the practices described in this policy.

Contact: joinprincipia@gmail.com

What we collect

Nothing is sent directly to us during ordinary app use. The Principia app contains no analytics or advertising SDK, tracker, or third-party code that phones home. Users need no Principia account, and the app never asks for an email address or contact details. You can optionally enter a display name to personalize reminders; it stays on your device.

The only content you submit directly from inside the app is what you deliberately send by opening Settings, then Send Feedback. Because that submission includes customer-support content and limited diagnostics, the App Store privacy label declares Customer Support and Other Diagnostic Data, linked conservatively to you, for App Functionality and never for tracking.

Apple-provided reporting: Apple may separately make App Store sales and subscription reports available to us. If a user has agreed to share diagnostics and usage information with app developers in their Apple device settings, Apple may also make usage metrics and crash information available through App Store Connect and Xcode. Principia does not embed an analytics SDK, create an advertising identifier, or send these reports itself. Apple controls that collection and applies its own privacy terms and reporting safeguards.

Apple’s App Store definition of data “collection” is narrower than some privacy laws. Even where we cannot see device or private iCloud data, the app still processes it locally to provide its features, as explained below.

Data stored on your device

Principia stores the information it needs to work:

• which equations you have revealed, and when;
• your streak history and milestones;
• favorites, reading preferences, and daily selections;
• quiz answers and quiz progress;
• a free-reveal allowance counter used to enforce the free tier;
• reminder settings and scheduled notification times;
• the optional display name, if you choose to set one; and
• recent feedback-send timestamps used locally to limit repeated submissions.

Preferences, reminder settings, the optional display name, and feedback rate-limit timestamps are device-only. They disappear when you delete the app. Reveal history, favorites, daily selections, quiz progress, and the free-reveal allowance may also sync through iCloud.

Settings > Delete Synced Data removes synced reveal history, daily selections, favorites, and quiz results. The free-reveal allowance is deliberately retained to prevent repeated free-allowance resets and may survive a reset or reinstall through iCloud. You can also manage Principia’s stored iCloud data through your Apple Account settings.

iCloud sync

If you are signed in to iCloud, selected progress can sync through your own private iCloud account using Apple’s CloudKit private database. This lets progress follow you across devices and survive reinstalls. We do not receive, see, or have access to this private database.

You can manage iCloud access by opening iOS Settings, choosing your Apple Account, then choosing iCloud. You can remove stored data through Manage Account Storage. Apple provides iCloud under its own terms and privacy policy; we do not determine how Apple operates your Apple Account.

Purchases

Subscriptions and the lifetime unlock are processed by Apple through the App Store. We never receive your payment details, billing address, or Apple Account credentials. Principia reads your entitlement status locally, including which plan is active and whether a trial is running, only to unlock features on your device. Apple provides sales and subscription reporting, which can include transaction and subscription activity, product, territory, and an Apple-generated subscriber identifier. Purchases, refunds, and cancellations are managed through your App Store account.

Notifications

Daily reminders, streak nudges, and eligible trial-ending reminders are scheduled locally on your device. They are not sent from our server, and their contents do not reach us. Notifications are optional and can be switched off in Principia or iOS Settings.

Sharing

If you share an equation card, Principia renders it on your device and passes it to the destination you choose through the standard iOS share sheet. That destination’s privacy practices then apply. Nothing is shared automatically.

Optional feedback

Principia includes an optional Send Feedback form in Settings. It is the only place where Principia lets you send content directly to us, and only when you tap Send. Sending requires an authenticated iCloud account. Apple-provided App Store reporting is separate and described above.

If you send feedback, we receive:

• the message you write, trimmed to a maximum of 1,000 characters;
• the category you choose: bug, idea, or other;
• your app version and build;
• your iOS version;
• a hardware model class such as “iPhone16,1,” never your user-set device name; and
• your language and region setting.

We do not ask for or attach your name, email address, or other contact information. Apple CloudKit also adds record metadata such as a creation timestamp and an account-scoped creator identifier. That is why the App Store label treats the submission as linked to you even though we do not receive a name or email.

Your submission is written to the CloudKit public database so the developer can review it. Principia has no feature for users to browse submissions. Production permissions are configured so that signed-in app users can submit feedback but cannot read anyone else’s submissions; only the developer can read them.

We use feedback only to understand the submission, diagnose problems, respond to support needs, and improve Principia. We retain a record only as long as reasonably necessary for those purposes, review stored feedback periodically, and then delete it unless a longer period is required by law or needed to protect the service.

There is no user-facing reference number or contact identifier attached to feedback. If you ask us to locate a submission, include its approximate date, category, and distinctive wording. We will make reasonable efforts, but those privacy-preserving limits may make identification or verification difficult.

Service providers and disclosure

We do not sell personal data or disclose it for advertising, profiling, or tracking. Apple processes information for iCloud, App Store transactions and reporting, opt-in usage and crash reporting, and CloudKit feedback as described above. The app also contains local open-source mathematics-rendering libraries; they send nothing anywhere.

Netlify delivers this website and may process standard request information as described in About this website. Those providers handle information for the stated service; no analytics provider, advertising network, tracker, or data broker receives it from us.

Children

Principia is a general-audience educational app and is not directed to children under 13. The app requires no account with us and has no advertising, tracking, chat, or social feature, and the optional display name never leaves the device.

A user could still type personal information into optional feedback. If you believe a child did so, contact us with the approximate submission date, category, and distinctive wording so we can make reasonable efforts to locate and delete it. Device-only data can be removed with Principia’s reset controls or by deleting the app; private iCloud data must be managed through the child’s Apple Account settings.

Legal basis

Where a legal basis is required, we rely on our legitimate interests in providing a functioning app for local processing, responding to support needs and improving Principia for optional feedback, and making this website available and secure for standard delivery information. We consider the limited and user-initiated nature of feedback and do not use it for unrelated purposes.

Private iCloud sync and App Store transactions also involve Apple under the terms of your Apple Account. Depending on your jurisdiction and the feature, Apple’s legal role may differ; Apple explains its own processing in its privacy materials.

Your rights and deleting data

Depending on the law that applies to you, you may have rights of access, correction, deletion, restriction, objection, and portability. Most app information is controlled directly on your device or in your Apple Account:

• Access and correction: review your progress in Principia and edit or remove the optional display name in Settings.
• Device-only data: use Principia’s reset controls or delete the app. Synced data and the retained free-reveal allowance are covered separately above.
• iCloud control: disable sync or remove stored data by opening iOS Settings, choosing Apple Account, then iCloud and Manage Account Storage.
• Feedback access or erasure: contact us with the approximate date, category, and distinctive wording. Identification and verification may be limited because feedback contains no name, email, or reference number.
• Portability: contact us about any right that applies. Principia does not currently provide a user export, and we cannot export private iCloud data we cannot access.

For a formal request, contact us. We will respond within the period required by applicable law. Under the GDPR, where it applies, this is generally one month. You may also complain to your local data protection authority; in the UK, this is the Information Commissioner’s Office.

About this website

This website is hosted by Netlify. When a page loads, Netlify may process standard request information such as your IP address, browser type, requested page, and timestamp to deliver and secure the site. IP addresses can be personal data under laws such as the GDPR.

The site uses only self-hosted type and image assets. It contains no analytics, advertising, behavioral tracking, or third-party font request. The Principia app itself does not contact Netlify.

If you pause the website’s decorative motion, the site stores that functional preference in your browser’s local storage. It stays on that device, is not transmitted to us, and is not used for analytics or tracking. You can remove it by clearing this site’s browser data.

If you join the website launch list, we receive the email address you choose to submit. That separate, one-notice use is explained in the launch list privacy policy.

Changes to this policy

If Principia’s data practices change, we will update this policy and its “last updated” date before the relevant change ships. Material changes will be explained clearly.