Privacy policy

HSM Studio's Last updated: May 25, 2026 GDPR compliant
Quick summary

01 Who we are

HSM Studio's is an independent studio founded by Vladimir Felix in La Paz, Baja California Sur (Mexico). We develop Guardians in direct collaboration with specialist medical residents, with the goal of making on-call scheduling no longer a daily headache.

For questions about this policy or to exercise your rights, email [email protected]. We reply personally within 48 hours.

02 What data we process

2.1 Data you create in the app

When you use Guardians you can record on-calls (name, dates, color, icon), notes (text, images, tags) and preferences (language, theme, color). This data is stored locally on your device: on iOS we use SwiftData; on Android we use Room (SQLite). We do not have access to it.

2.2 Sync between devices

iOS: if you have iCloud Sync enabled in Settings, Apple syncs your database across your devices using your Apple ID. Data travels directly from your device to iCloud — we never see it. Apple is the data controller; see their policy at apple.com/privacy.

Android: Google may automatically back up Guardians data to your Google Drive account if Auto Backup is enabled in Settings → System → Backup. Just like iCloud, data goes directly to Google — we do not see it. See Google's policy at policies.google.com/privacy.

2.3 Technical identifiers

  • Anonymous install identifier (Firebase, RevenueCat) for aggregate stats and purchase validation.
  • iOS: Apple's advertising identifier (IDFA) only if you allow it via the native App Tracking Transparency prompt.
  • Android: Advertising ID and, on Android 13+, Privacy Sandbox / Topics API according to system permissions. You can reset or disable it from Settings → Privacy → Ads.

2.4 Purchases

Guardians Pro purchases are processed through the App Store (iOS) or Google Play Billing (Android). We receive an anonymous receipt (validated by RevenueCat) that only indicates whether you purchased or not. We do not see your name, email or payment details.

03 Third-party services

Guardians uses the following services. Each one has its own privacy policy:

ServiceUsed forPolicy
Apple iCloud (iOS)Optional syncapple.com/privacy
Google Auto Backup (Android)Optional backuppolicies.google.com/privacy
Google AdMobAdspolicies.google.com/privacy
FirebaseAnalytics + Crashlyticsfirebase.google.com/support/privacy
RevenueCatPurchase processing (receipt validation)revenuecat.com/privacy
Apple App Store / Google PlayPayment processingEach platform's policy

04 Ads and tracking privacy

Free-plan users see banners and interstitials served by Google AdMob.

  • iOS: on first launch we show the native App Tracking Transparency prompt. If you say no, ads still appear but are not personalized.
  • Android: we use the Advertising ID and, on Android 13+, the Topics and Attribution APIs of the Privacy Sandbox when available. You can reset or disable your Advertising ID from system Settings → Privacy → Ads.

If you purchase Guardians Pro you stop seeing ads entirely on either platform.

05 Data of minors

Guardians does not collect personal data from any user, minor or adult. On-calls, notes and preferences live only on your device (and, optionally, in your own iCloud or Google Drive). We have no access and keep no copies.

Additionally, the app is not directed at children under 16 in line with GDPR recommendations.

06 Your rights (GDPR)

As a user you have the following rights over your information:

  • Access — know what data we hold about you.
  • Rectification — correct incorrect data directly from the app.
  • Deletion — wipe your data from Settings → Data management.
  • Objection — ask us to stop processing your data: uninstall the app or turn off sync.
  • Portability — export your data in a readable format (coming soon).
  • Withdraw consent — revoke ad tracking in Settings → Privacy → Tracking.

To exercise any right contact [email protected]. We respond within 30 days.

07 Data retention

The data you create lives on your device while you have the app installed. When you uninstall Guardians, all local data is removed.

  • iOS: if you enabled iCloud Sync, the data remains in your iCloud until you delete it from Settings → Apple ID → iCloud.
  • Android: if Auto Backup is enabled, Google keeps a copy in your Drive until you delete it from Settings → Google → Backups.

Anonymous analytics and advertising data is retained according to Google and RevenueCat policies.

08 Security

Locally, data is stored in the app's private storage — protected by the operating system and only accessible by Guardians. On iOS this is the app sandbox; on Android the private folder at /data/data/com.hsmstudios.guardians readable only by our app.

Optional syncs (iCloud on iOS, Auto Backup on Android) travel end-to-end encrypted thanks to Apple and Google respectively.

09 Changes to this policy

If we update this policy, the new version is published here with an updated date. We recommend checking back occasionally. The "Last updated" date above always reflects the current version.

10 Contact

Questions, feedback, or exercising rights? We are one reply away.

HSM Studio's

We reply personally within 48 hours.

This policy is published in compliance with EU Regulation 2016/679 (GDPR).