Zzz Polyrhythm — Privacy Policy

App Name:

Zzz Polyrhythm (iOS)

Last Updated:

May 29, 2026

Effective Date:

2026-05-29

1. Our Privacy Stance

This app ("Zzz Polyrhythm", "the App") respects your privacy to the fullest extent. All rhythm-related configurations (time signature, BPM, layered rhythms, voices, saved presets) and your language preference are processed and stored entirely on your device, and are never transmitted to any server operated by us.

However, to keep the App available for free, we display banner and full-screen (interstitial) ads through a third-party advertising network. Ad delivery involves transmitting your IP address and, where permitted, the iOS Identifier for Advertisers (IDFA) to the ad network.

2. Information We Collect

2.1 Rhythm Configurations & Presets

• Time signature, BPM, voices, layered rhythms, and shuffle settings you adjust on screen are held in memory.
• When you save a named preset (a Premium-only feature), it is written to the App's private sandboxed storage area as a JSON file.
• None of this data is transmitted to our servers or any cloud service.

2.2 Language & Locale Settings

• The display language you select from the hamburger menu (System, English, Japanese, Chinese, Korean, Spanish, Portuguese) is saved to the device's UserDefaults.
• The OS locale is used only for date/number string formatting; it is not stored or transmitted.

2.3 Subscription Purchase Information

• When you toggle "Ad-free (Premium)" on, a subscription is purchased through the App Store using Apple's In-App Purchase (StoreKit) framework.
• The transaction identifier and entitlement status (active / canceled) are obtained from the App Store and stored as a flag in the device's UserDefaults.
• Payment information such as credit card numbers is handled entirely by Apple; the App never receives or stores it.

3. How We Use Information

Collected information is used solely for the following purposes:

• Controlling on-device metronome playback
• Saving and loading local presets at your request
• Displaying the UI in your selected language
• Toggling ad display and unlocking restricted features based on subscription status

4. Where Information Is Stored

Rhythm configurations, presets, language preference, and the subscription status flag are all stored only on your device.

• Saved to the App's private sandboxed container

• No transmission to our servers
• No iCloud or other cloud sync
• No mechanism by which the developer can access your data

Data associated with ad delivery is obtained and managed independently by the third-party ad network, separately from data stored by the App.

5. Sharing with Third Parties

We do not sell or provide the following to third parties:

• Rhythm configurations or preset contents
• Language selection history
• Detailed app usage activity
• Personally identifying information

However, for ad delivery, the third-party advertising network receives your IP address, the iOS Identifier for Advertisers (IDFA) (only when you have granted tracking permission via the system's App Tracking Transparency prompt), device/OS information, and ad impression/interaction metrics. The App's developer cannot access this data, nor do we link it with on-device rhythm settings or share such linkage with third parties.

6. Third-Party Services

6.1 Advertising Network (Ad Delivery)

To keep the App free, we deliver banner and interstitial ads through a third-party advertising network.

Data Sent	IP address, IDFA (only when tracking permission has been granted), device/OS information, ad impression/interaction metrics
Data NOT Sent	Rhythm settings, saved presets, language preference, any other on-device data
Purpose	Ad delivery, display, frequency capping, performance measurement, fraud prevention
Data Controller	The ad network provider (processed per its respective privacy policy)

You can control tracking by the ad network from the iOS Settings app under Settings → Privacy & Security → Tracking, and limit ad tracking from Settings → Privacy & Security → Apple Advertising.

6.2 In-App Purchase (Subscriptions)

The "Ad-free (Premium)" subscription is provided through Apple's In-App Purchase (StoreKit) framework. All payment processing, billing management, and cancellation are handled by the App Store.

• The App only receives the transaction identifier and entitlement status from the App Store.
• The App never obtains or stores payment information such as credit card numbers or bank account details.
• You can cancel your subscription anytime via iOS Settings → [your name] → Subscriptions.

6.3 Tracking Consent (App Tracking Transparency)

In compliance with Apple's App Tracking Transparency framework, the App requests permission before allowing the third-party ad network to access the IDFA for cross-app tracking. If you do not grant permission, only non-personalized ads are shown. To comply with the GDPR (EU/EEA and UK) and U.S. state privacy laws (CCPA/CPRA, etc.), users in eligible regions may additionally be presented with a consent form for personalized ad delivery.

7. Required Permissions & Capabilities (iOS)

Capability / Permission	Purpose
Network access	Loading ads and communicating with the App Store for In-App Purchase
App Tracking Transparency (optional)	Asks for your consent before allowing the ad network to use the IDFA for personalized ads. You can decline.
In-App Purchase entitlement	Subscription processing via the App Store

No additional permissions for location, microphone, camera, contacts, photos, notifications, or background execution are required.

8. What We Do NOT Use

• Analytics SDKs
• Crash reporting SDKs
• User authentication or login
• Social media integration
• Backend servers operated by the developer
• Cloud processing (all audio processing is done by the on-device C++ engine)
• Location, microphone, camera, contacts, photos, background execution

* We use a third-party advertising network solely for ad delivery and Apple's In-App Purchase framework solely for subscriptions.

9. Data Deletion

When you uninstall this App, all data created by the App on your device (saved presets, language preference, subscription status flag, etc.) is completely deleted as iOS removes the entire app sandbox.

To delete individual presets, use the in-app "Load" dialog (Premium feature) — check the items you want to remove and tap delete.

10. Children's Privacy

This App does not knowingly collect personal information from children under 13. Any ads shown in the App are delivered in accordance with the ad network's policies and your selected tracking and consent preferences.

11. Open-Source Libraries

This App uses the following open-source software and Apple frameworks:

• SwiftUI (Apple) — UI framework
• Combine (Apple) — reactive event handling
• AVFoundation / Core Audio (Apple) — audio playback infrastructure
• Swift Concurrency (Apple) — asynchronous programming
• Foundation Codable (Apple) — JSON serialization
• StoreKit (Apple) — In-App Purchase framework
• AppTrackingTransparency (Apple) — tracking consent framework

Integration and configuration of these libraries are the original implementation of the App developer.

12. Changes to This Policy

This policy may be updated without prior notice. Significant changes will be communicated along with App updates. This page is always the most current version.

13. Contact

For inquiries regarding this policy, please contact us through this App's App Store listing.