D4 Privacy Policy

Effective 13 October 2026 · Fort Mill Ventures

The short version

D4 does not collect, store, sell or share any personal data. Everything D4 does happens on your iPhone.

Sound

When you choose D4 sound science as your audio output, the sound of the app you are using passes through D4 on your iPhone, is enhanced in memory, and is played on your iPhone speaker. It is never recorded, saved or sent anywhere.

Microphone

D4 never uses the microphone and does not ask for microphone access.

Information kept on your iPhone

D4 keeps your settings (for example the sound mode chosen for each app) and a small technical log of when D4 turned on and off, so it can recover if iOS stops it. This stays inside D4 on your iPhone. It is deleted when you delete D4.

Notifications

If you allow notifications, D4 schedules local notifications on your iPhone, for example to tell you D4 was closed. No server is involved.

No accounts, analytics, ads or tracking

D4 has no account, no sign-in, no analytics, no advertising and no third-party code that collects data. D4 does not track you across apps or websites.

Children

D4 collects no data from anyone, including children.

Changes

If this policy changes, the new version will be posted here with a new effective date.

Contact

Questions: [email protected]

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