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, and who processes it.

Summary

• 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.

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 base App is a paid download through Apple. 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.

Analytics, advertising, and tracking

Changeover does not include third-party advertising SDKs or sell personal information. We do not use your journal content 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: use the support / contact options on the Changeover App Store listing, or open an issue on github.com/trevornogues/changeover-public-pages.