Privacy Policy

1. Who is responsible

Tennis Tension Lab is provided by SEOKWON KONG (공석원 개인 개발자), an independent developer in the Republic of Korea. Questions about this policy or your data can be sent to aflhzv@gmail.com.

2. Data handled by the app

Measurement audio

The microphone is used only while you measure a racquet. Short tap sounds are analyzed in memory on your device and then discarded. Tennis Tension Lab does not save or upload an audio recording.

Racquet and measurement records

The app stores the information you enter or create, including racquet labels and models, string and hybrid setups, stringing dates, tension references, measurement results, playing-time notes, feel feedback, replacement thresholds, units, and language settings. A randomly assigned Firebase user ID is used to keep synchronized records separate. You do not need to provide a name, email address, or phone number to use the app.

Photos

If you choose a racquet photo, the app creates a cropped copy in its private on-device storage. The original library image is not copied into cloud sync, and the cropped photo is not uploaded by the current version.

Location

If the nearby stringing-shop map is available and you choose the locate control, your current location is used temporarily to center the map and show your position. Tennis Tension Lab does not retain that coordinate. The map provider may process the request under its own privacy policy.

Support messages

If you contact support, the email address, message, and any attachment you choose to send are used only to answer and resolve your request.

3. Why the data is used

• Measure and compare string tension estimates.
• Organize racquets, string jobs, trends, feedback, and preferences.
• Synchronize app records across installations associated with the same anonymous ID.
• Protect the service, prevent abuse, and diagnose a support request.

The app does not sell personal data, show targeted advertising, or track you across apps or websites.

4. Service providers and international processing

Google Firebase Authentication and Cloud Firestore provide anonymous sign-in and cloud synchronization. Google may process a user identifier, IP address, and basic device, app, and request metadata to operate and secure those services. Static catalog and guide media are delivered through Amazon Web Services and CloudFront. Google Maps is contacted only when the optional map feature is available and used. These providers may process data in countries outside your own under their contractual and legal safeguards.

5. Storage, retention, and deletion

On-device records remain until you delete them, reset synchronized data, or remove the app. Cloud-synchronized records remain while the anonymous Firebase account is active. In the app, open Settings and choose Reset synced data to remove racquets, string jobs, measurements, feedback, and preferences from that account and synchronized devices, then restore sample data. Service-provider backups and security logs may take additional time to expire under the provider’s retention schedule.

If you cannot use the in-app reset, email support from the device concerned. Include no information you do not want to share; we may need a non-sensitive app identifier shown in a diagnostic step to locate the correct anonymous record.

6. Security and children

Cloud data is sent over encrypted connections and separated by Firebase access rules. No system can be guaranteed completely secure, so the app limits what it sends and does not upload measurement audio or racquet photos. Tennis Tension Lab is a general-audience sports utility and is not directed to children under 13.

한국어 요약

마이크는 라켓 텐션 측정 중에만 사용됩니다. 두드리는 소리는 기기 메모리에서 분석한 뒤 즉시 폐기되며 녹음 파일로 저장하거나 업로드하지 않습니다. 라켓·스트링 세팅·측정 결과와 환경설정은 익명 Firebase ID를 기준으로 동기화될 수 있습니다. 이름, 이메일, 전화번호는 앱 사용에 필요하지 않으며 광고 추적이나 개인정보 판매를 하지 않습니다. 설정의 동기화 데이터 초기화에서 저장 기록을 삭제할 수 있습니다. 문의: aflhzv@gmail.com

7. Changes

This page will be updated when the app’s data practices materially change. The effective date at the top shows the latest revision.