Privacy Policy

Last updated: May 9, 2026

Stem Splitter — Vocal Remover & Karaoke Maker ("the App") is published by Bulpara Inc ("we", "us", "our"). This policy describes how we collect, use, and protect information when you use the App.

1. Audio Files & Stems

• Your audio never leaves your device. All stem separation runs on-device using a Core ML model that runs on the Apple Neural Engine.
• The App does not upload, transmit, stream, or store your audio files or generated stems on our servers.
• Source audio and separated stems live in the App’s sandbox on your iPhone, and are removed when you delete the App or the corresponding project.
• If you choose to export a stem or share a custom mix via the iOS share sheet (Files, Voice Memos, AirDrop, Messages, GarageBand, etc.), you control where it goes — we do not see it.
• DRM-protected tracks (Apple Music, audiobooks, etc.) are rejected at import. The App cannot and will not attempt to bypass DRM.

2. The Separation Model

• The neural-network model used for stem separation is downloaded once on first launch from cdn.bulpara.com (or bundled with the App, depending on the release). The download is the model file only — no audio is transmitted.
• After the one-time download the App functions fully offline. Toggling Airplane Mode does not disable separation.
• The model file is verified by checksum and stored in the App’s sandbox.

3. Data We Store Locally

• Project history: Source filename, duration, separation status, and timestamps for each project. Stored locally via SwiftData.
• Generated stems: Separated audio files (vocals, drums, bass, other) saved in the App’s document directory.
• Preferences: Default export format, default export destination, theme, and background-processing toggle.
• Monthly usage counter: A local counter that resets on the first of each month to enforce the free-tier separation limit. No counter data is transmitted off-device.
• Purchase status: Subscription state is managed by Apple’s StoreKit and cached locally for feature gating.

4. Permissions We Request

• Files / iCloud Drive: Only the audio file you explicitly pick is imported into the App’s sandbox. We do not enumerate your file system.
• Notifications (optional): Used only to notify you when a long track finishes processing in the background. You can disable in iOS Settings.
• The App does not request microphone, photo library, contacts, or location access.

5. Third-Party Services

The App uses the following third-party services:

• Apple App Store / StoreKit: Manages subscriptions and purchases. Governed by Apple’s privacy policy.
• Bulpara CDN (cdn.bulpara.com): Hosts the one-time separation model download. Standard server access logs (IP address, timestamp, user agent) are retained for 30 days for abuse prevention. No audio is ever transmitted to this CDN.
• Google AdMob (free tier only): Displays banner and interstitial ads to free-tier users. AdMob may collect device identifiers for ad personalization. Audio files and generated stems are never shared with AdMob. See Google’s Privacy Policy.

Premium subscribers see no ads and trigger no AdMob requests.

6. Data Storage and Security

• All audio files, generated stems, project history, and preferences are stored locally on your device.
• No audio data, stem files, or device-identifiable content is transmitted to or stored on our servers. We have no servers that hold user audio.
• Purchase verification uses Apple’s secure StoreKit framework.
• The App’s core separation feature works completely offline after the one-time model download.

7. Data Sharing

We do not sell your personal data. We do not share your audio files or stems with any third party. AdMob may collect device-level data for ad personalization (free tier only); audio content is excluded.

8. Your Rights

You can:

• Delete individual projects (and all associated stems) from the Library tab inside the App
• Delete the App to remove all local audio, stems, history, and preferences
• Disable Notifications from iOS Settings at any time
• Request information about data handling by contacting us at privacy@bulpara.com

9. Children’s Privacy

The App is rated 4+ and is not intended to collect data from children under 13. Because the App does not collect personal data, this is enforced by design.

10. Changes to This Policy

We may update this policy from time to time. Changes will be posted on this page with an updated "Last updated" date.

11. Contact Us

If you have questions about this privacy policy, contact us at:

privacy@bulpara.com