Privacy Policy

App: Nightgrit  ·  Developer: VesperKiln  ·  Last updated: 22 August 2026

Summary

• Your audio never leaves your iPhone. Recording and grinding detection run entirely on the device. We cannot hear, read, or retrieve your recordings.
• The app does show ads and does measure how it is used. To do that, it and its advertising partners collect device and usage data, including your advertising identifier.
• Some of that data is used to track you across apps and websites owned by other companies, for advertising. iOS asks your permission first.

1. Your Recordings Stay on Your Device

Nightgrit listens through the microphone while you sleep and uses an on-device neural network to mark sounds that resemble teeth grinding.

• Audio is written to the app's private storage on your iPhone and is never uploaded to us or to anyone else.
• Detection runs offline on the device. No audio, transcript, or detection result is sent to a server.
• Older clips are removed automatically. You can delete any night yourself from the History screen, and uninstalling the app removes all recordings and results.

Microphone access is used only while a recording session is running, for this purpose.

2. Information Collected for Advertising and Analytics

Nightgrit is free and supported by advertising. The app and the partners listed in section 4 collect the following categories of data. This list matches the App Privacy information shown on our App Store product page.

Collected and linked to you, and used to track you:

• Device ID — the Apple Advertising Identifier (IDFA), vendor identifier (IDFV), and identifiers assigned by our measurement partner
• Advertising Data — which ads were requested, shown, clicked, and what revenue they generated
• Coarse Location — an approximate region (typically country or city level) derived from your IP address; the app does not request precise location and does not use GPS
• Product Interaction — app opens, session length, and in-app milestones such as reaching a given level or a given amount of time in the app
• Performance Data — launch times, load failures, and similar technical measurements
• User ID — an identifier assigned to your installation by our measurement partner
• Other Data — other technical values sent by the advertising SDKs, such as device model, operating system version, and network type

Collected but not used to track you:

• Crash Data and Other Diagnostic Data — to find and fix defects
• Other Usage Data — aggregate measurements of how the app is used
• Customer Support — only the contents of an email you choose to send us

These categories are used for analytics, app functionality, our own advertising, and third-party advertising. None of your recorded audio and none of the grinding-detection results are included in any of them.

3. Tracking and the App Tracking Transparency Prompt

When you first open Nightgrit, iOS shows the App Tracking Transparency prompt asking whether the app may track you across apps and websites owned by other companies.

• If you allow, our advertising partners may use your IDFA to measure advertising and to show you more relevant ads.
• If you ask the app not to track, the IDFA is not made available to the app and is not used for cross-app tracking. The app still works, and you will still see ads, but they will be less relevant.
• You can change this at any time in Settings → Privacy & Security → Tracking.

4. Third-Party Services

Nightgrit includes the following third-party SDKs. They receive the data described in section 2 and handle it under their own privacy policies.

• Adjust — attribution and analytics: tells us which campaign an install came from and counts in-app milestones. Adjust privacy policy
• AppLovin MAX — advertising mediation. MAX selects which advertising network fills each ad slot, so additional advertising networks integrated through MAX may also receive advertising and device data. AppLovin privacy policy

We do not sell your personal information. We do not use social media plugins, and the app has no accounts, no login, and no cloud sync.

5. Children's Privacy

Nightgrit is not directed to children under 13, and we do not knowingly collect personal information from them. Because the app shows advertising and uses tracking, we do not recommend it for children. If you believe a child has used the app and you would like their data removed, contact us at the address in section 9.

6. Data Security

Recordings and detection results are held in the app's private container and protected by the standard file protection built into iOS. Data sent to the partners in section 4 is transmitted over encrypted connections. No method of storage or transmission is completely secure, and we cannot guarantee absolute security.

7. Your Choices and Rights

• Stop tracking — use the App Tracking Transparency setting described in section 3.
• Reset your advertising identifier — Settings → Privacy & Security → Tracking and Apple's advertising controls.
• Delete your recordings — delete individual nights from the History screen, or uninstall the app to remove everything stored on the device.
• Access, correction, or deletion of data held by our partners — depending on where you live, you may have the right to request access to, correction of, or deletion of personal data. Email us and we will pass the request to the relevant partner.

8. Changes to This Privacy Policy

We may update this policy when the app or the applicable law changes. The date at the top shows when it was last revised. Material changes will be reflected here before they take effect.

9. Contact Us

Questions about this policy or about your data:

Email: marlowe@vesperkiln.info
Developer: VesperKiln