Privacy policy for GuitarDaily
Developer: Kostas Martzi (Konstantinos Martzivanos). App: GuitarDaily, Android package com.kostasmartzi.guitardaily. This policy describes the Android app version 1.2.0 and associated account, cloud synchronization, and Google Play access services. For privacy inquiries, email k.martzivanos@icloud.com.
1. Your choice: guest or cloud account
You can use GuitarDaily's available guest features without creating a Firebase account. Guest progress is stored on your device. If you choose an account, you can sign in with Google or register with email and password, then synchronize supported practice data with your other Android and iOS devices signed into the same account. You control whether to copy guest practice into the account. Signing out returns you to the separate guest profile.
2. Authentication data
For optional account registration and sign-in, Firebase Authentication (Google) processes your account user ID, email address, authentication credentials and linked sign-in provider information. Google sign-in may also provide a display name or profile information. Firebase and sign-in providers process connection information, such as IP address, user agent, and security signals, for authentication, abuse prevention, and account security. Your email is used for login, password resets, verification, and account support—not for advertising or marketing mailing lists. Passwords are handled by Firebase Authentication; we do not store a copy in the practice database.
3. Cloud practice data
When you sign in and synchronize, Cloud Firestore (Google Firebase) stores practice data associated with your Firebase user ID. Depending on which features you use, this can include completed exercises and program days, practice sessions, durations and dates, exercise history and feedback notes, metronome BPM, technique settings, ratings, favorites, streak/achievement information, weekly goals, and selected preferences. A pseudonymous device/sync identifier may be used to reconcile practice totals across devices. Data is used to restore and synchronize your GuitarDaily experience, not to profile you for advertising. Local account-scoped copies can remain on a device while offline.
4. Purchases and subscriptions
Google Play handles payment methods, checkout, and subscription management. For access verification, the app sends Google Play purchase records, including purchase tokens and signed transaction details, to GuitarDaily's verification service associated with guitardailyapp.com. The service checks entitlement with Google Play, supports restoring eligible previous paid downloads, and may process order identifiers provided by you for legacy purchase restoration. We use these details to enable paid features, prevent fraudulent access, and resolve access issues. The verification service may process IP address, request time, and short-lived security/rate-limiting information. We do not receive your payment-card details or banking credentials. Google maintains its own billing and legally required transaction records.
5. Device-only data and permissions
GuitarDaily stores local preferences, device-specific state, temporary playback/session controls, optional notification choices, and guest practice on the device. The tuner uses the microphone only when you grant permission and start it; microphone audio is processed on your device to estimate guitar pitch and is not uploaded or retained as an audio recording by GuitarDaily. Practice reminders are scheduled locally. You can export or import backups through your device's file picker. An exported file is stored wherever you choose, and is not uploaded to GuitarDaily by the export operation. Third-party storage providers you select handle copies under their own policies.
6. How data is used and who processes it
- App functionality and account management: account login, verification, cloud synchronization, restoring progress, and subscription access.
- Security and fraud prevention: sign-in safeguards, purchase verification, and abuse protection.
- Service providers: Google Firebase Authentication and Cloud Firestore process account/practice data on our behalf; Google Play processes purchase and subscription information; website and verification-service hosting providers process essential network requests.
We do not sell your personal data or use your synced practice history for ad targeting. The Android 1.2.0 build does not include a separate advertising or app-owned analytics/crash-reporting SDK. External websites you choose to visit may have separate policies.
7. Security and international processing
Firebase uses encryption in transit and at rest. Firestore access rules restrict cloud practice records to the authenticated account holder. We limit cloud records to practice and account functionality. Google Firebase Authentication processes personal data in the United States, while Cloud Firestore data is stored in its configured region and may involve international service-provider processing. Consult Firebase privacy and security information for details. No online system can guarantee absolute security.
8. Retention, account deletion, and your choices
Cloud practice records and account information are kept while you maintain the account, unless you delete it or request deletion. In GuitarDaily go to More → Account & Cloud Sync → Open account settings → Delete account and synced data, confirm, and reauthenticate. The app deletes the synced practice records and then your Firebase Authentication account. We have tested this flow on Android. You can also request deletion without the app at GuitarDaily Account Deletion or email k.martzivanos@icloud.com using your sign-in email. We may verify ownership before processing the request.
Some limited security deletion markers and provider logs or backups may remain for security and technical reasons and are removed according to the relevant service retention schedules. Firebase states that certain authentication data can take up to 180 days to disappear from backup systems after deletion. Account deletion does not erase exported backup files or practice stored in an independent guest profile or on offline devices; you must remove these separately. A Google Play subscription does not automatically end when your GuitarDaily account is deleted: cancel it through Google Play subscriptions. Google Play may retain purchase records as required by its policies or law. If you want an individual practice entry removed without closing the account, contact us for assistance; availability of selective cloud-data deletion is not guaranteed.
9. Support, children, and changes
If you email support, we receive the email address and message you voluntarily provide and retain correspondence only as necessary to respond and meet applicable obligations. Parents and guardians may contact us regarding their child's information or deletion requests. The app does not request birth dates. We may update this policy when data practices change; the date and applicable version will be updated. For privacy questions, contact k.martzivanos@icloud.com.