Privacy Policy

Changeover (“the App”) is a personal tennis journal published by Trevor Nogues (“we,” “us”). This policy explains what data stays on your device, what leaves the device when you use optional Changeover AI features, what anonymous usage statistics we collect, and who processes it.

Summary

• Changeover launched in 2026. It is a free App Store download; Changeover AI is an optional paid subscription.
• Your match, practice, hit, and equipment journal lives on your phone.
• There is no sign-up, email account, or social login.
• We do not sell your data or show ads.
• If you use Changeover AI (premium), a sanitized snapshot of relevant journal history is sent to our backend and then to OpenAI so the companion can answer. Other people’s names are removed first.
• We do not keep a copy of your journal on our servers.
• We collect anonymous usage statistics (for example “a match was logged” or “a share card was created”) to understand which features are used. These never include your notes, scores, opponent names, or the questions you ask Changeover AI, and you can turn them off in Settings.

Data stored on your device

The App stores your tennis journal locally (matches, practices, casual hits, equipment and setups, notes, ratings, and cached AI results) using on-device storage. That journal is not synced by Changeover to other devices. It may be included in your device’s own backups (for example iCloud Backup) according to your system settings. That is Apple’s backup, not a Changeover cloud account.

On-device features such as Trends, Patterns, streak, and Competition run entirely on your phone and do not require a network connection.

No Changeover account

Changeover does not ask you to create an email or social account. Purchases use your Apple ID through the App Store. Restore Purchases re-links a subscription on a new phone via Apple.

Anonymous identity for premium AI

When Changeover AI is available, the App silently creates an anonymous identifier (Firebase Anonymous Authentication). That identifier is not a profile. It is used only so our Cloud Functions can:

• enforce usage limits, and
• confirm that the Changeover AI subscription is active (via RevenueCat).

Reinstalling the App typically creates a new anonymous identifier. Your subscription still restores through Apple.

On our backend we may store usage counters and a cached entitlement flag keyed to that anonymous identifier. We do not store your journal entries there.

Changeover AI: what leaves the device

Changeover AI (narrative insights and Ask Changeover) is optional and requires the premium subscription. When you refresh insights or ask a question, the App builds a structured snapshot of relevant history on device, then:

1. Replaces opponent and partner names with stable aliases (for example “Player A”) in structured fields and in free-text notes.
2. Sends that sanitized snapshot (and, for Ask, your question after the same name scrub) to our Cloud Functions over HTTPS.
3. Our Cloud Functions call OpenAI’s API to generate the response. We set store: false so responses are not kept as OpenAI application state. OpenAI states that API data is not used to train their models. OpenAI may retain limited abuse-monitoring logs under its own policies unless Zero Data Retention is approved for the project.
4. The answer is returned to the App and cached on your device for offline use. We do not retain the journal snapshot or the answer content on Changeover servers after the request completes.

Locations, scores, ratings, and your own words in notes may be included because they are what the companion reasons about. Do not put information in notes that you are not willing to send for analysis when using Changeover AI.

If Firebase is not configured or you are offline without a usable cache, AI features degrade gracefully; the rest of the journal still works.

Purchases

The App is free to download through the App Store. Changeover AI is an optional auto-renewable subscription processed by Apple. We use RevenueCat to help verify entitlements. Apple and RevenueCat process payment-related data under their own privacy policies. We do not receive your full payment card details.

Anonymous usage statistics

The App uses Google Analytics for Firebase to collect anonymous usage statistics so we can see which features people use and where the App can be improved. Examples of what is recorded: that a match, practice, hit, or piece of equipment was logged and which optional fields were filled in (as yes/no flags); that a share card was created and how it was shared; that Changeover AI insights were refreshed or a question was asked; screens viewed; purchase and restore events; and general app and device information (app version, iOS version, device model, language, and country or region derived from your IP address, which Google does not store).

Usage statistics never include the content of your journal. We do not send opponent or partner names, scores, locations, ratings, notes, equipment names, or the text of questions you ask Changeover AI. Usage statistics are not linked to your name, email, or Apple ID; they are associated with a random app-instance identifier generated by Firebase on your device, which is reset if you reinstall the App. We do not use the Advertising Identifier (IDFA) and do not track you across other companies’ apps or websites.

You can turn usage statistics off at any time in Settings → About → “Share anonymous usage stats”. The rest of the App works the same either way. Google processes this data as our service provider under the Firebase Privacy and Security terms; event data is retained by Google for a limited period (currently up to 14 months) before it is deleted or aggregated.

Advertising and tracking

Changeover does not include third-party advertising SDKs, does not sell personal information, and does not use your journal content or usage statistics for advertising.

Children

The App is not directed at children under 13, and we do not knowingly collect personal information from children under 13.

Your choices

• You can use the journal without purchasing or using Changeover AI.
• You can stop using AI features at any time; cancel the subscription in your Apple ID subscriptions settings.
• Deleting the App removes the on-device journal (unless restored from a device backup).

Changes

We may update this policy as the product changes. The effective date at the top will change when we do. Continued use of the App after an update means you accept the revised policy.

Contact

Questions about privacy: changeoverjournal@gmail.com, the support options on the Changeover App Store listing, or open an issue on github.com/trevornogues/changeover-public-pages.