Privacy Policy

Last updated: 25 June 2026

Kyuhachi (“the app”, “we”, “us”) is an iOS app for tracking your progress in the 九州八十八湯 (Kyushu 88 Hot Springs) challenge. This policy explains what data the app collects, why, and how it is handled.

Kyuhachi is an independent, fan-made app. It is not affiliated with or endorsed by the official 九州八十八湯 organisation or 88onsen.com.

Information we collect

• Account information. When you create an account we store the email address associated with it. You sign in with Sign in with Apple (Apple may provide a private relay email address) or with an email address and password. The app does not offer anonymous use.
• Your challenge data. The onsen visits you record — including the onsen, the date and time, your reported transport mode, any notes, and any photos you attach — together with the challenges and imported routes you create.
• Location. With your permission, the app uses your device location to show your position on the map and to surface onsens near you. Location is used to power these features; the app does not keep a continuous history of where you have been.
• Photos. If you attach a photo to a visit, the app accesses the photo you select (or one you take with the camera) and stores it so it can be shown on your visits.

How your data is stored

Your account and challenge data are stored using Google Firebase (Authentication, Cloud Firestore, and Cloud Storage). Data is tied to your account and, under our security rules, is accessible only to you. The app also keeps a local offline copy on your device so it works without a connection.

How we use your data

We use your data only to provide the app’s features: signing you in, saving and displaying your visits and challenges, showing nearby onsens, and tracking your progress and tiers.

We do not sell your data, use it for advertising, or use third-party analytics or tracking SDKs.

Sharing

We do not share your personal data with third parties except:

• Google Firebase, which stores and processes data on our behalf as our infrastructure provider.
• Apple, when you choose Sign in with Apple.

Data retention and deletion

Your data is retained while your account exists. You can delete individual visits and challenges within the app. To delete your account and all associated data, contact us via the link below and we will remove it.

Children

Kyuhachi is not directed at children under 13 and we do not knowingly collect data from them.

Changes to this policy

We may update this policy from time to time. Material changes will be reflected by the “Last updated” date above.

Contact

Questions about this policy, or requests to delete your account and data, can be raised by opening an issue at https://github.com/PetrCala/kyuhachi/issues.