Last updated 12 September 2026

Privacy, without
the mystery.

SleepFast is developed by YUZI in the Netherlands. This policy covers the iPhone app and sleepfast.yuzi.nl. For privacy requests, contact info@yuzi.nl.

What stays on your iPhone

Your preferences, sessions, saved sound blends, streaks, and self-reported time to fall asleep are stored locally. YUZI does not receive these records. Device backups may include app data according to your Apple backup settings.

Optional Apple and device features

• Location and weather. With your permission, coarse location is sent directly to Apple WeatherKit to request weather-informed wind-down suggestions. SleepFast does not store your location. You can instead describe how your room feels manually.
• Camera biofeedback. With camera permission, fingertip brightness is processed in real time on your iPhone to estimate a pulse for relaxation feedback. Camera frames are not recorded, saved, or transmitted. This is not a medical measurement.
• Apple Health. If enabled, SleepFast can write your self-reported sleep-onset information to Apple Health. It does not request permission to read your Health data. Health records and permissions are managed separately in Apple's Health app.
• Sleep coach. On compatible devices, Apple's on-device Foundation Models generate suggestions locally. When that model is unavailable, the app uses its built-in guidance. Coach input is not sent to YUZI or an external AI service.
• Purchases. Apple handles App Store payments and purchase restoration. SleepFast verifies purchase entitlements using Apple's StoreKit. YUZI does not receive your card details through the app.

Apple handles its services under Apple's privacy policy. Permissions are optional; declining them does not prevent use of the core breathing and sound features.

Website visits and support emails

Our hosting server processes technical request information, such as IP address, requested page, browser information, and request time, to deliver the website and protect it from abuse. We do not install advertising cookies, tracking pixels, or website analytics. Technical logs are used for operation, security, and troubleshooting.

If you email us, we receive your email address and the information you choose to send. We use it to respond and resolve your request. Please avoid sending medical records or other sensitive information that is not necessary for support.

Purpose, access, and retention

We process support correspondence to answer your request, and technical website data for our legitimate interest in operating a secure website. Hosting and email providers process that information to provide these services. We do not sell personal information or use sleep data for advertising.

We keep support correspondence and technical records only as long as needed for the relevant support, operational, security, or legal purpose. We may preserve relevant records where needed to investigate abuse or comply with a legal obligation.

Your choices and rights

You can revoke camera and location permission in iOS Settings, and Health permission in the Health app. Deleting SleepFast removes its local app data; separate device backups and previously saved Apple Health records are controlled through Apple's settings.

For personal information held by YUZI, you may request access, correction, deletion, restriction, portability where applicable, or object to processing by emailing info@yuzi.nl. We may need to verify a request. You may also contact your local data protection authority, including the Dutch Autoriteit Persoonsgegevens.

Audience

SleepFast is a general wellness tool and is not directed specifically at children. It does not create user profiles or collect age information in the app.

Policy changes

We will publish changes on this page and update the date above. If a change requires your consent, we will request it before the affected processing begins.