Privacy Policy for Mask Day
Effective date:November 2, 2026
Developer:Theo Gaius
Contact:gaiuspub@gmail.com
This Privacy Policy explains how the Mask Day Android app ("Mask Day", "the app", "we", "us") handles information when you use it. We built Mask Day to work without an account, and we keep the information we handle to a minimum.
## 1. Summary
- Your supply list, replacement dates, spare stock counts, and replacement history are stored **only on your device**. We do not have servers that receive or store this information.
- We do **not** require you to create an account, and we do not ask for your name, email address, or phone number.
- The free version shows ads from **Google AdMob**, which may collect device identifiers and usage data to show and measure ads.
- In-app purchases are processed by **Google Play** and managed by **RevenueCat**, which receive the purchase information needed to confirm your Pro access.
- We do **not** sell your personal information.
## 2. Information stored on your device
Mask Day stores the following information locally on your device so the app can work:
- The names of your CPAP supplies, their replacement intervals, and the dates you last replaced them
- Spare stock counts (Pro feature)
- Your replacement history
- App settings, such as your reminder preferences
We do not transmit this information to our own servers, and we cannot see it. It stays on your device until you delete it in the app, clear the app's data, or uninstall the app.
If you have Android device backup turned on, Android may include the app's data in your device backup (for example, Google One / Google Drive backup). That backup is handled by Google under your Google account settings and Google's privacy policy, not by us.
**Health information:** Mask Day is a supply-replacement tracker. It does not collect medical records, sleep data, therapy data, or diagnoses, and it does not connect to your CPAP machine. The supply names you enter stay on your device and are not shared with us or with advertising partners.
## 3. Information collected by third-party services
Mask Day uses the following third-party services. Each has its own privacy policy that governs how it handles data.
### Google AdMob (advertising)
The free version of Mask Day shows banner ads served by Google AdMob. To serve, personalize (where permitted), measure, and prevent fraud in ads, AdMob may collect:
- Device identifiers, including the Android Advertising ID
- IP address and approximate location derived from it
- Device and app information (device model, operating system version, app version)
- Ad interaction data (for example, ad views and taps)
- Diagnostic data, such as crash and performance information related to ads
Where required by law (for example, in the European Economic Area, the United Kingdom, and Switzerland), we will ask for your consent before personalized ads are shown. You can reset or delete your Advertising ID, or opt out of ad personalization, in your device's settings under **Settings → Google → Ads** (wording may vary by device).
Pro subscribers and lifetime purchasers do not see ads.
Google privacy policy: https://policies.google.com/privacy
How Google uses data from partner apps: https://policies.google.com/technologies/partner-sites
### Google Play Billing (purchases)
If you buy Mask Day Pro, the payment is processed by Google Play. We do not receive or store your payment card details. Google Play shares purchase information with us (such as the product purchased, the purchase date, and a purchase token) so we can confirm your purchase.
Google Play privacy policy: https://policies.google.com/privacy
### RevenueCat (purchase management)
We use RevenueCat to check your purchase status and unlock Pro features. RevenueCat receives:
- Purchase history and receipt or token data from Google Play
- A random, anonymous app user ID created by the RevenueCat software (not linked to your name or email)
- Basic device and app information (such as operating system version, app version, country, and language)
RevenueCat uses this information only to provide purchase and subscription services to us.
RevenueCat privacy policy: https://www.revenuecat.com/privacy
## 4. Notifications
Mask Day schedules reminder notifications on your device, 7 days before a supply is due and on the due date. These reminders are created and delivered **locally** by your device. They do not use a push notification server, and no reminder content is sent to us. You can turn notifications off at any time in your device settings.
## 5. Permissions the app uses
- **Internet access:** used to load ads and verify purchases.
- **Notifications:** used to show supply replacement reminders.
- **Run at startup:** used only to restore your scheduled reminders after your device restarts.
Mask Day does not access your contacts, camera, microphone, photos, files, or precise location.
## 6. How we use information
The limited information described above is used to:
- Provide the app's core features (tracking supplies and reminding you)
- Verify purchases and unlock Pro features
- Show ads in the free version
- Keep the app working reliably and prevent fraud
## 7. Sharing of information
We do not sell your personal information. Information is shared only with the service providers described in Section 3, for the purposes described there, or when required by law.
## 8. Data security
Information processed by our third-party services is sent over encrypted connections (HTTPS). Data stored on your device is protected by your device's own security features, such as your screen lock and Android's app sandboxing.
## 9. Data retention and deletion
- **On-device data:** you can delete any item or history entry in the app. Uninstalling Mask Day, or clearing its data in **Settings → Apps → Mask Day → Storage**, permanently removes everything stored by the app.
- **Purchase data:** Google Play and RevenueCat keep transaction records as needed for accounting, legal, and fraud-prevention purposes. To request deletion of RevenueCat data linked to your anonymous app user ID, contact us at the email above.
- **Advertising data:** you can reset or delete your Advertising ID in your device settings. Google's retention practices are described in its privacy policy.
Because we do not operate user accounts, there is no account to delete.
## 10. Children's privacy
Mask Day is intended for adults who use CPAP equipment. It is not directed to children under 13 (or the minimum age in your country), and we do not knowingly collect personal information from children. If you believe a child has provided information through the app, contact us and we will take appropriate steps.
## 11. Your rights
Depending on where you live (for example, under the GDPR in the EU/UK or the CCPA/CPRA in California), you may have the right to access, correct, delete, or restrict the use of your personal information, to object to processing, and to withdraw consent. Because almost all app data stays on your device, you can exercise most of these rights directly in the app. For anything else, including information held by our service providers, contact us at the email above and we will respond within the time required by law.
## 12. Changes to this policy
We may update this Privacy Policy from time to time. When we do, we will post the new version at this page and update the effective date above. Significant changes may also be announced in the app.
## 13. Contact us
If you have questions about this Privacy Policy, email us at:
gaiuspub@gmail.com