YOUR DATA, YOUR CHOICE
Privacy policy
Muscle Atlas (근육도감) is a 3D muscle learning app. This notice describes Google sign-in, on-device preferences, banner and detail ads, optional rewarded ads, and support in the current Android prototype.
At a glance
- You can explore without signing in.
- Muscle visibility, view and color settings remain on your device. Account-based synchronization is not available.
- Delete your account in the app or request deletion by email. See account deletion instructions.
1. Operator and contact
Service: Muscle Atlas (근육도감)
Operator and privacy contact: 김승태
Email: muscleatlashelp@gmail.com
2. Information and purposes
| Category | Information and purpose |
|---|---|
| Optional Google sign-in | Firebase user ID, email, name, Google profile information such as photo URL, account creation and last sign-in information. Used for sign-in and account management. The app displays your name and email; it does not ask for your Google password. |
| Authentication security | Firebase Authentication processes IP addresses and user-agent information for authentication and abuse prevention. |
| Device preferences | Selected and hidden muscles, view, colors, language choice and guest entry state restore your browsing preferences. The app does not upload these settings to a server. |
| Ad-free reward | The device stores the reward completion time, device elapsed time and a boot marker to restore the 20-minute ad-free period. App code does not upload this record to your account or a server. This record is excluded from Android cloud backup and device transfer. |
| Age range | The latest Android prototype (1.10 and later) stores your selection of under 16, 16–17, or 18 or older on this device for access and ad protections. It is not uploaded to your app account. We do not collect your birth date or identity documents. Teen ad protection and consent-handling signals are sent to Google's advertising and UMP services. |
| Advertising SDK | Google Mobile Ads SDK may process IP addresses (which can indicate approximate location), app and ad interactions, diagnostics, and device or account-related identifiers for advertising, analytics and fraud prevention. The app does not separately attach your name, email or muscle browsing history to ad requests. |
| Public information pages | When you visit privacy or account deletion pages served through Firebase Hosting, Hosting processes the incoming IP address for abuse prevention and usage analysis and retains it for a few months. |
| Support and deletion requests | Your email address, message and replies are used to respond and verify the requester. Do not send passwords, verification codes or identity documents. |
The app currently has no health-record entry, health-data integration or payment features. Separate Firebase Analytics and Crashlytics collection code is not connected. The advertising SDK's own diagnostics and analytics are described above.
3. External services and international processing
We use Google Firebase for accounts and public information pages, Google AdMob and UMP for ads and advertising privacy choices, and Gmail for support. Google and the affiliates operating these services process the information below, which may be transferred from your device to servers abroad.
- Authentication: During registration, sign-in and account management, the sign-in and security information in section 2 is sent over encrypted internet connections to Firebase Authentication. It is processed in the United States for authentication and account management.
- Information pages: Visiting these pages sends your IP address to Firebase Hosting for abuse prevention and usage analysis. Hosting uses Google's global infrastructure; we do not select a single processing country.
- Advertising: During UMP privacy checks, ad requests and interactions, the advertising information in section 2 may be sent to Google advertising services. Google LLC and its affiliates process information under Google's privacy policy in the United States and other countries where their servers operate.
- Support: Email addresses, messages and replies are processed through Gmail and may be processed in countries where Google operates servers. The operator deletes these emails 30 days after resolution.
Sign-in and support information is processed to provide the account or support service you request. You can explore without signing in and contact us to request account deletion or to stop processing. Account features cannot be provided if account processing stops. See section 5 for advertising choices and section 4 for retention.
Service terms, processing locations and privacy contacts:
- Firebase privacy and security · Firebase service terms
- Google advertising SDK disclosures
- Google privacy policy and contact · Google data center locations
4. Retention and deletion
- Account: Firebase processes account data while the account exists. The Firebase user is deleted after successful in-app deletion or after the operator verifies and processes an email request. Firebase states that related authentication data is removed from live and backup systems within up to 180 days after deletion begins; authentication IP logs may be retained for a few weeks.
- Device settings: May remain until app storage is cleared. Account deletion does not clear these settings.
- Ad-free reward record: The last record is overwritten by the next reward or removed when app storage is cleared. An expired record no longer removes ads. Signing out or deleting an account does not reset it.
- Advertising: Google's practices and your advertising choices apply. Deleting the app account does not delete your Google account or all information separately maintained by Google.
- Email: Deletion requests, general support emails and related replies are deleted 30 days after the request has been resolved.
5. Your choices and requests
Contact the support email to request access, correction, deletion or restriction of account data processing, or to withdraw consent where processing relies on consent. Where necessary, we verify ownership of the email used to sign up. Email deletion requests are processed within 7 days after verification, with a result notification. In the app, use My account (내 계정) → Delete account (회원 탈퇴).
Where required, an advertising privacy options button appears under My account → Privacy information. The app requests ads only after UMP confirms ads may be requested. If this check fails, muscle exploration remains available. The current APK uses test ads and is configured to request non-personalized ads. Non-personalized ads may still process information needed for ad delivery, diagnostics and fraud prevention.
The latest Android prototype (1.12 and later) includes a bottom banner and an ad below muscle details. If you choose and complete a rewarded ad, both placements are hidden on this device for 20 minutes. Muscle exploration remains available if you decline or close the ad. The time continues to elapse while the app is closed.
6. Device settings and protection
Clear local settings through Android Settings → Apps → Muscle Atlas → Storage. This also resets the device's sign-in state and exploration preferences. Google authentication and advertising services use encrypted communications. The app does not directly save login tokens in web localStorage.
7. Audience and changes
The planned initial audience is people aged 16 and older in the United States and South Korea. The latest Android prototype (1.10 and later) asks you to select your age range before first use. This is self-declared and is not identity-based age verification. Selecting under 16 restricts access. Before age selection, and for people who select under 16, the app does not start ad consent checks or request ads.
Ages 16–17 receive Google's teen ad protections without requests for ad-personalization consent. Ages 18 and older also receive non-personalized ad requests with a maximum ad content rating of G, and advertising privacy choices where required. These ranges are used for ad settings, not to determine legal adulthood.
Use My account or Sign in → Privacy information → Change age range to update the selection saved on this device. Update it if someone else uses the device or you move into a different age range. Changes remove the previous banner and detail ad and check the new settings. Updating overwrites the saved range; clearing app storage removes it. Account deletion alone does not reset it. If saving is unavailable, the choice applies only to the current session.
We will update this notice and its effective date and provide any required choices when data practices or the service change.