Koyomiaruki
Koyomiaruki Privacy Policy
iOS app “Koyomiaruki — walking with the moon and the seasons”
Koyomiaruki is built on the principle of collecting no personal information. There is no account registration, and the app never obtains your name, email address, or location. Records such as step counts and photos are stored entirely on your device and are never sent to the developer's or any third party's servers.
Information handled on your device
- Steps — To display your step count and reflect it in the scenery, the app reads steps from the motion sensor (Core Motion) and Health (HealthKit). It only reads and never writes. Health data is never used for advertising or provided to third parties.
- Photos and discovery notes — To keep a record of your walks, the app stores references to photos you take, along with your notes, on the device.
- Settings — Your chosen prefecture and notification settings are stored on the device.
All of this lives only on your device and disappears when you delete the app (the photos themselves remain in your iOS photo library).
Network communication
The app communicates externally for only two purposes.
- Fetching weather forecasts — To receive forecasts from the Japan Meteorological Agency (www.jma.go.jp), the app sends the forecast-area code for the prefecture you selected. By the nature of network communication, your IP address reaches the agency's servers, but the developer never receives it.
- Displaying ads — The app uses Google AdMob to display ads. Ads are configured as non-personalized, and no ads based on behavioral tracking are shown. The app never asks for tracking permission (App Tracking Transparency). To serve ads and prevent fraud, Google's SDK may send your IP address and information about your device to Google. For details, see the Google Privacy Policy (https://policies.google.com/privacy) and Google's advertising policies (https://policies.google.com/technologies/ads).
Information handled by the ad SDK
The App Privacy section on the App Store lists the following information handled by Google's SDK in the course of displaying ads. All of it serves ad delivery and fraud prevention; none of it is linked to your identity or used for behavioral tracking.
- Identifiers (device ID) — A device identifier may be used for frequency capping and fraud prevention.
- Usage data (advertising data) — Whether an ad was displayed or tapped.
- Diagnostics (crash and performance) — Diagnostic information that keeps the ad SDK running reliably.
The app itself never collects or stores any of this.
Notifications
Tidings such as full moons and solar terms are local notifications assembled entirely on your device. There is no push notification server, and the app performs no external communication for notifications.
Changes to this policy
If the content changes, it will be announced on this page.
Contact
Effective date: August 15, 2026