Privacy Policy — kerf
kerf is a single-player block stacking game for iPhone. It has no user accounts, no sign-up, no advertising, and no analytics or tracking software. This policy explains the small amount of data the app touches and where it goes.
Data stored on your device only
Your settings (sound, haptics, theme, accent colour, app icon, block texture, share card theme) and your local high scores, run count and daily streak are stored on your iPhone using Apple's standard UserDefaults storage. This information never leaves your device, is not sent to us, and is deleted when you delete the app.
Game Center — leaderboards and achievements
Game Center is optional and switched off until you choose to use it. The app does not sign you in at launch and never prompts you on its own.
The first time you tap a Game Center entry point (Menu → Leaderboard, or Settings → Game Center), the app asks for your consent and explains what will happen. Only if you agree and sign in does the app begin sending data.
Once you are signed in, the app sends the following to Apple's Game Center service at the end of a ranked run:
- your score and tower height for that run, submitted to the leaderboard of the mode you played;
- your achievement progress.
Apple associates this with your Game Center account and displays it publicly on global leaderboards under your Game Center nickname, alongside other players. We do not operate these leaderboards and we do not run a server of our own: the data goes directly from your device to Apple and is handled under Apple's Privacy Policy. We can read only the aggregate rankings that Game Center shows to any player.
You can stop this at any time by signing out of Game Center in iOS Settings, and you can manage or remove your Game Center data through Apple. If you never sign in, no score of yours is ever uploaded and the game remains fully playable with local high scores.
Purchases
kerf offers one optional non-consumable in-app purchase, "kerf Complete". Payment is processed entirely by Apple through the App Store; we never see or receive your payment details, card number, or billing address.
To unlock your purchase on your devices and to support Restore Purchases, the app uses RevenueCat, Inc., a purchase-management service acting as our processor. RevenueCat receives the App Store purchase receipt and your device's vendor identifier (IDFV — an anonymous, per-vendor identifier that resets when you delete the app). We do not create an account for you in RevenueCat and do not send it your name, email address, or Game Center identity, so this data is not linked to your identity. It is used only to determine whether the purchase is active.
What the app does not do
- No advertising, no ad networks, no advertising identifier (IDFA), and no App Tracking Transparency prompt — we do not track you across apps or websites.
- No analytics or crash-reporting software of any kind.
- No access to your contacts, photos, camera, microphone, location, or health data.
- No user-generated content, no messaging, no social features beyond Apple's own Game Center.
- No sale or sharing of personal data with anyone, for any purpose.
Summary
| Data | Where it goes | Purpose |
|---|---|---|
| Settings, local high scores | Your device only | Running the game |
| Scores, achievement progress | Apple Game Center, only after you consent and sign in | Leaderboards and achievements |
| Purchase receipt, device identifier (IDFV) | Apple, RevenueCat | Unlocking and restoring the in-app purchase |
Children
kerf is rated 4+ and is suitable for all ages. It does not knowingly collect personal information from children. It contains no advertising and no user-to-user communication. The only feature that transmits anything is Game Center, which requires an explicit tap and is governed by Apple's own parental controls and Screen Time settings.
Your rights
Because the app holds no account and no server-side profile, there is nothing for us to look up, export, or delete on your behalf. Deleting the app removes all locally stored data. Game Center data is controlled through your Apple Account; purchase records are controlled through Apple and, where applicable, RevenueCat. If you have a question or a request regarding your data, write to arslanyakup56@gmail.com and we will respond within 30 days.
Changes
If this policy changes, the revised version is published at this address with a new "last updated" date. Material changes affecting how data is handled will also be noted in the app's release notes.