Privacy Policy

Information We Collect

When you use RhythmBattle, we collect the following:

• Account Info: Your username, display name, email address, and a securely hashed password. We never store your password in plain text.
• Email Address: Collected at registration and used exclusively for password reset. We do not send marketing emails or share your email with third parties.
• Motion Data: Accelerometer and gyroscope readings from your device during dance sessions. This data is processed in real-time on your device to generate scores and is not stored raw.
• Dance Session Scores: Your rhythm, intensity, and flow scores, session duration, and peak acceleration for each dance.
• Track Information: The name and artist of the song you danced to, stored with your dance session record.

How We Use Your Data

Your data powers the fun stuff:

• Scoring: Motion sensor data is used in real-time to calculate your dance scores.
• Leaderboards: Your scores are used to rank you against other dancers globally.
• Profile & Stats: We aggregate your dance history to show you personal stats like total dances, best scores, and average performance.
• App Improvement: We may analyze anonymized, aggregated data to improve scoring algorithms and the overall experience.
• Password Reset: Your email address is used solely to send a one-time password reset email when requested. No other emails are sent.

Music & Audio

RhythmBattle includes built-in genre playlists and exclusive Shift+Ctrl AI music tracks:

• Audio tracks are streamed from Google Cloud Storage and are not downloaded or stored on your device.
• No personal data is transmitted when streaming music — tracks are served as standard media files.
• The name and artist of the track you danced to is stored with your dance session record for your history and stats.

Data Security

We take security seriously:

• Passwords are hashed using industry-standard algorithms before storage.
• Login credentials on your device are stored using platform-native secure storage (iOS Keychain / Android EncryptedSharedPreferences).
• All communication between the app and our servers is encrypted via HTTPS.
• Motion sensor data is processed locally on your device and only aggregated scores are transmitted.

Sensor Permissions

RhythmBattle requests access to your device's motion sensors (accelerometer and gyroscope). Here's the deal:

• We only use sensor data during active dance sessions.
• Sensor data is processed in real-time and not stored in raw form.
• You can deny sensor access, but the dance scoring features won't work without it (kind of the whole point of the app).
• We never use sensors for tracking, advertising, or any purpose outside of dance scoring.

Data Retention

We keep your data for as long as you use the app:

• Your account info and dance history are retained while your account is active.
• If you want your data deleted, contact us and we'll remove everything.
• Leaderboard entries may be retained in anonymized form even after account deletion.

Third-Party Services

We use the following third-party services:

• Google Cloud Storage: For hosting and streaming Shift+Ctrl AI music tracks and built-in genre playlists. No personal data is shared with Google beyond standard server request logs.
• Google Cloud Run: Our backend server runs on Google Cloud Run. Request logs may be retained by Google per their standard cloud logging policies.
• Resend: Used to deliver password reset emails. Your email address is transmitted to Resend solely for this purpose and is not used for any other communication.
• Expo / React Native: Our app framework, which may collect basic crash analytics.

Children's Privacy

RhythmBattle is intended for users 13 years of age and older. We do not knowingly collect personal information from children under 13. If you believe a child under 13 has created an account, please contact us and we'll promptly remove it.

Changes to This Policy

We may update this privacy policy from time to time. When we do, we'll update the "Last updated" date at the top. We recommend checking back occasionally, but honestly, we'll try not to change things too dramatically. We'll always be upfront about what data we collect and why.