Privacy Policy

Last updated: 23 June 2026

Harmonize is a vocal-harmony trainer. This policy explains, in plain language, what the app does and does not do with your information.

The short version

• Harmonize has no accounts and asks for no personal information.
• Your practice progress (streaks, notes nailed, lessons finished) is stored only on your device.
• Audio from your microphone is processed live on your device to detect the pitch you sing. It is never recorded, saved, or sent anywhere.
• The app sends a small amount of anonymous, aggregate usage and crash data so we can fix bugs and understand which features are used. This data cannot be used to identify you.

Microphone

Harmonize needs your microphone to hear the notes you sing and give you instant pitch feedback. The audio is analysed in real time on your device and is immediately discarded. No recording is created, stored, or transmitted. You can revoke microphone access at any time in your device Settings; the app will prompt you to re-enable it if you try to practice.

Information stored on your device

The following stay on your device only and are never uploaded:

• Your detected or chosen vocal range and voice type.
• Practice progress: best streak, total notes nailed, and which lessons you have completed.
• App preferences.

Deleting the app removes all of this data.

Anonymous analytics and crash reporting

To improve the app we collect anonymous, aggregate data through two privacy-focused services:

• Aptabase (usage analytics): records coarse events such as the app being opened, a practice session starting, a lesson being completed, or a vocal range being set. Aptabase does not collect personal data and uses an ephemeral session identifier with no persistent device or user id, so individual users cannot be singled out or tracked across apps. See aptabase.com/legal/privacy.
• Sentry (crash reporting): records anonymous diagnostic information if the app crashes or hits an error, so we can fix it. We do not attach any identifying information to these reports. See sentry.io/privacy.

We do not use this data for advertising, we do not sell or share it with data brokers, and we do not track you across other apps or websites. Because of this, the app does not show an App Tracking Transparency prompt.

Children's privacy

Harmonize does not knowingly collect personal information from anyone, including children.

Changes to this policy

If this policy changes, the updated version will be posted at this address with a new "last updated" date.

Contact

Questions about your privacy or this policy? Email me@deetercesler.com.