Privacy Policy

Knock on Wood / The Book of Wood · Last updated: October 16, 2026

Knock on Wood (“the app”) is published by XChiral (“we”, “us”). This policy explains what the app does and does not do with your information. The short version: we do not run ads, we do not track you, and we do not sell your data.

1. What stays on your device

Most of the app works entirely on your phone and never leaves it:

• Which Wood you have selected, which page of the book you were last on, and your custom story and knock messages.
• Your “Keep It Close” event (its title and date), including the Lock Screen countdown (Live Activity).
• Your in-progress Co-Author draft before you submit it.
• Whether you have unlocked The Book of Wood club (a local flag; the purchase itself is verified by Apple).

Motion sensor. If you allow it, the app uses your phone’s motion sensor only to detect a physical knock. Motion data is processed on the device and is never stored or sent anywhere.

Photos. The app can create a Lock Screen wallpaper and offers it through the system share sheet. It only asks to add an image to your Photos if you choose “Save Image”. We never read your photo library.

2. The Draft Room (what is sent to our servers)

If you use “Become a Co-Author” to submit ideas, like ideas, or report ideas, that information is stored on our servers (Google Firebase) so other people can see it. This includes:

• An anonymous user ID. The app creates an anonymous account automatically in the background. There is no sign-up, email, or password. The ID only lets us show you which ideas are yours, let you edit or delete them, and make sure you can like an idea only once.
• Your idea: the title and description you write, and an image if you choose to attach one.
• Your name, only if you choose to enter one (it is optional; otherwise your idea shows as “Anonymous”).
• Likes and reports you make, and the time things were created.

Public: your idea’s title, description, image, optional name, and like count are visible to all users of the app. Please do not put personal information, such as a phone number, address, or anyone’s private details, in an idea or image.

Reports you send are visible only to us, and are used to review and remove content that breaks our rules.

3. Purchases

The one-time unlock is an in-app purchase handled entirely by Apple. We never see or store your payment details or Apple ID. We only receive confirmation from Apple that the purchase was made, so we can unlock the content on your device.

4. What we do not do

• No advertising, and no advertising identifiers.
• No third-party analytics or tracking SDKs, and no cross-app or cross-site tracking.
• We do not sell or rent your information.

5. Service providers

We use Google Firebase (Authentication and Cloud Firestore) to run the Draft Room. Google processes the data described in section 2 on our behalf under its own terms and privacy policy. Apple processes purchases through the App Store.

6. User content and community rules

Ideas must be kind and appropriate. We remove content that is offensive, hateful, harassing, sexual, illegal, or that infringes someone else’s rights, and we may remove content at our discretion. You can report any idea inside the app (the “Report” link under it); reported ideas are hidden for you immediately and reviewed by us.

7. Keeping and deleting your data

• You can edit or delete any idea you submitted at any time, from the “Mine” tab of the Draft Room. Deleting an idea removes its text, image, and name from our servers.
• Data kept only on your device is removed when you delete the app.
• Because accounts are anonymous, we cannot find your data by name. To ask us to delete something you submitted, contact us (below) and tell us the idea’s title so we can locate it.

8. Children

The app is not directed at children under 13, and we do not knowingly collect personal information from them. If you believe a child has submitted personal information, contact us and we will remove it.

9. Security

Data is sent over encrypted (HTTPS) connections and stored with Google Firebase security rules that limit who can create, edit, or delete data. No system is perfectly secure, so we cannot guarantee absolute security.

10. Changes to this policy

If we change this policy, we will update the date at the top. Material changes will be noted in the app or its App Store listing.

11. Contact

Questions, deletion requests, or content concerns: contact@xchiral.com