Privacy policy

Effective November 5, 2026

yssdev (“we,” “us,” or “our”) handles information related to the Akari iPhone app (the “App”) and this website (akari.yssdev-app.com) as described in this policy.

1. Information stored on our servers

To count how many people are awake right now and show them on the globe, the App sends the following information to our servers.

• Anonymous ID: An ID the App creates automatically for each device (using Google's Firebase Authentication). It isn't linked to your name or email address. If you switch to a new phone, you get a new ID.
• Light data: The region where you turned on your light (the country and the state, prefecture, or similar region you chose on the globe), the date of the night you turned it on, the times it started and ended, how it ended (such as whether you tapped “Done” or it turned off automatically), the time it's scheduled to turn off automatically, and the color of your light.
• Sticker data: The type and time of each sticker you sent while your light was on. We don't keep a record of who it was sent to.
• Counts for each light: The number of people who were up with you and the number of stickers you received.

2. Information used during communication but not recorded

• Network information such as your IP address: For communication to work, this reaches Cloudflare, which hosts our servers, and Google, which handles anonymous IDs. We don't record it. However, to prevent excessive requests, Cloudflare's system counts the requests from each IP address in 10-second intervals.
• Proof that the App is genuine: Generated with Apple's App Attest and Google's Firebase App Check, and used only to verify the requests we receive.
• App and Firebase versions: Used for purposes such as verifying requests from older versions of the App.

3. Information kept only on your device and in your iCloud

The App doesn't send the following information to our servers. We can't read it either.

• Records (your light history), keepsakes, and private notes: Kept on your device and in your iCloud (a private database provided by Apple). How iCloud handles them is governed by Apple's Privacy Policy.
• Your place and app settings: Kept only on your device.
• Purchases: Handled by Apple's App Store. We don't receive payment information such as card numbers.

4. Purposes of use

• To count the number of people with their lights on right now, the number of people who were up with you, the number of stickers you received, and the number of people in each region, and to show them in the App
• To show lights and stickers on the globe
• To verify that requests come from the genuine App, and to prevent unauthorized requests and overuse
• To respond to requests to delete accounts

We don't use this information for advertising, tracking, or analytics, and we don't sell it.

5. Retention periods

Our servers don't keep track of whose history is whose. Information linked to an anonymous ID is deleted after 40 days. After that, all that remains are counts that can't be traced to anyone.

6. Companies that handle information on our behalf

We use the services of the following companies and entrust them with handling information. All of them are U.S. companies, and information may be processed on servers outside Japan.

• Cloudflare, Inc.: Servers (Workers, D1, and R2) and delivery of this website
• Google LLC: Firebase Authentication (anonymous IDs) and Firebase App Check (verifying that the App is genuine)
• Apple Inc.: iCloud (storing records, keepsakes, and notes), App Attest, and the App Store (purchases)

7. Sharing with others

We don't share the information we collect with any other person or company, except in cases based on laws and regulations and when we entrust its handling to the companies listed in Section 6.

8. Deleting your account

You can delete your account anytime from “Settings” › “Delete account” in the App. When you do, the following are deleted immediately:

• Light and sticker data on our servers for that device's anonymous ID
• The anonymous ID (Firebase account)
• Records, keepsakes, and notes on your device and in iCloud

If you're offline, the information on your device is deleted right away, and the information on our servers is deleted once you're back online.

The following remain after deletion:

• Counts that can't be traced to anyone (sticker counts per minute and the number of people in each region)
• Information linked to anonymous IDs from devices you used before (because we can't verify which IDs are yours, deletion can't remove it; it's deleted automatically after 40 days)
• Server backups (deleted within 30 days)

9. Disclosure and other requests

Because we don't hold information that identifies users, such as names, we may not be able to confirm which information belongs to the person making a request. You can delete the information on our servers yourself anytime from “Settings” › “Delete account” in the App. For other requests, please reach us through the contact page below.

10. About this website

This website doesn't use cookies, analytics, or ads. Fonts are also served from this website, not loaded from outside services. Cloudflare receives network information such as your IP address in order to deliver the pages.

11. Security

Communication between the App and our servers is encrypted (HTTPS). Our server logs record only summaries of errors, and never include tokens, the content sent, IP addresses, or anonymous IDs.

12. Children's information

Akari is an app for parents and caregivers looking after a crying baby at night. We don't collect information about your child. Anything you write in your private notes is kept only on your device and in your iCloud.

13. Changes to this policy

If we change this policy, we'll announce it on this page and show the date of the change. We'll give advance notice of important changes in the App or on this page.

14. Contact