Privacy Policy
Last updated: July 2026
1. Principles
Otolog (the "App") is designed with the privacy of you and your students first. It has no server and requires no account. All data you enter or save — including student names, grades, lesson days, guardian notes, method-book progress, assigned pieces, lesson notes, and tuition records — is stored only on your device.
2. Data collection
The developer does not collect, obtain, or transmit any personal information about you or your students through the App. Its App Store privacy label is "Data Not Collected".
3. About your students' information
Most students recorded in the App are minors. The App never asks students or guardians to create an account, and never sends their information off your device. You may enter a nickname instead of a real name.
4. Network access
The App does not need a network connection to view or enter records. Communication occurs only when you make an in-app purchase (Otolog Pro) through the App Store, or restore that purchase. This is handled by Apple's StoreKit, and the developer receives no information identifying the purchaser.
5. Encrypted backup
Backup files exported from Settings are encrypted with a password you choose (AES-GCM). Where you store the exported file — on the device, in the Files app, on external storage, or in a cloud service — and how you manage it afterwards is entirely up to you. The developer cannot access the file. If you lose the password, no one — including the developer — can restore it.
6. Face ID / Touch ID
App lock uses Apple's LocalAuthentication. Biometric data is never shared with the App or the developer; only the success or failure of authentication is returned.
7. Third parties & analytics
The App uses no advertising SDKs, analytics SDKs, or tracking, and shares no data with third parties.
8. Your responsibility
Complying with the laws that apply to collecting and handling your students' and their guardians' personal information is your responsibility. The App stores data on your device by design, but this does not remove every risk — including loss or theft of the device and how you handle backup files. This page is general information, not legal advice.
9. Changes
If this policy changes, this page will be updated.
10. Contact
freetokyo2020@yahoo.co.jp (Developer: freetokyo)
How the Android version handles your data
The following describes the Android version (Android 8.0 and later). Everything above applies to iOS; only the points below differ on Android.
Your records are stored in a local database (Room) on your device. They are never sent to the developer's servers.
Both cloud backup and device-to-device transfer are disabled (allowBackup="false" plus data_extraction_rules.xml). To move to a new device, export a backup yourself from inside the app.
The only external service used is Google Play Billing (purchases). Google processes all payments; card details never reach the developer.
The only device permission the app requests is biometric unlock. It is asked for only when you use the matching feature, and declining leaves the rest of the app usable.
Uninstalling the app deletes the data on your device. With backup and transfer disabled, no copy remains outside it.
Controller, contact and your rights
This app is provided by freetokyo, an independent developer, who acts as the data controller. For any question about this policy or about personal data, contact freetokyo2020@yahoo.co.jp. We normally reply within five business days.
If you are in the EU, the EEA or the UK, the GDPR gives you the right to access, rectify, erase, restrict and port your personal data, to withdraw consent and to object to processing. You may also lodge a complaint with your national supervisory authority.
If you are a California resident, the CCPA/CPRA gives you the right to know, delete and correct the personal information collected about you, and to opt out of its sale or sharing. We do not sell or share personal information.
Where this app stores data only on your device, we have no access to it, so most of these rights are exercised directly on the device: delete or export inside the app, or delete the app. We will still answer any request you send us.
Retention: on-device data is kept until you delete it or remove the app. Support emails are deleted 24 months after the request is closed.