This Privacy Policy explains what information we collect when you use the GlucoLine application (the "App"), why we collect it, and your rights over it. It is issued by the developer identified in Section 1 ("we", "us", "our"). By using the App, you agree to this Policy.
Data controller: Aytuğ Altınok (individual
developer)
Contact: altinokaytug@gmail.com
GlucoLine is an independent companion app. We are not affiliated with, endorsed by, or sponsored by Abbott, FreeStyle, Libre, or LibreLinkUp.
When you connect GlucoLine to LibreLinkUp, you provide your LibreLinkUp email and password. We use these credentials to authenticate against LibreLinkUp on your behalf and to read the glucose values your sensor shares through that service. These credentials, along with the most recent glucose reading and a short history needed to draw charts and power widgets, are stored on our backend (hosted on Google Firebase in the United States/EU).
We use Firebase Crashlytics to collect crash reports and Firebase Performance to measure app reliability. These reports contain technical information about the crash and do not contain your glucose values or LibreLinkUp credentials.
We use Mixpanel and Firebase Analytics to understand how features are used so we can improve the App. Events are pseudonymous (linked to a random device ID) and do not include your name, email, or glucose values.
In-app purchases and subscriptions are processed by Apple and by our subscription infrastructure provider, RevenueCat. Apple provides us with transaction status; RevenueCat stores purchase receipts associated with a pseudonymous app user ID so that your Pro features follow you across devices.
| Purpose | Legal basis |
|---|---|
| Authenticate to LibreLinkUp and show your glucose readings | Performance of a contract (Art. 6(1)(b)) |
| Store credentials so widgets keep working while the app is closed | Performance of a contract (Art. 6(1)(b)) |
| Deliver push notifications for range / trend alerts | Performance of a contract (Art. 6(1)(b)) |
| Process glucose values (special-category health data, Art. 9) | Explicit consent (Art. 9(2)(a)) — you choose to connect a sensor |
| Crash diagnostics and bug fixes | Legitimate interests (Art. 6(1)(f)) |
| Product analytics (pseudonymous) | Legitimate interests (Art. 6(1)(f)) |
| Subscription management | Performance of a contract (Art. 6(1)(b)) |
We share the minimum information necessary with the following processors, each bound by a data-processing agreement:
We do not share data with advertisers, data brokers, or resellers. We do not sell personal information as defined under the California Consumer Privacy Act (CCPA).
Our processors operate globally. Your data may be transferred to and processed in the United States and other countries outside your own. When this happens, transfers are protected by Standard Contractual Clauses or equivalent safeguards published by the respective processors.
| Data | Retention |
|---|---|
| LibreLinkUp credentials | Until you sign out or delete the app |
| Recent glucose readings (rolling window) | Up to 24 hours on our backend; on-device history per your setting |
| Push token | Until it becomes invalid or you delete the app |
| Crash reports | Up to 90 days (Firebase default) |
| Analytics events | Up to 14 months (Mixpanel / Firebase default) |
| Purchase receipts | As required by tax and accounting law (typically up to 10 years) |
If you are located in the European Economic Area, the United Kingdom, or Switzerland, you have the following rights regarding your personal data. Many of these rights are also available to users in other countries under local law.
GlucoLine is rated 4+ on the App Store and may be used by all ages. Use by minors should be supervised by a parent or guardian, who is responsible for the LibreLinkUp account credentials entered in the app. We do not knowingly collect personal data from a child without parental consent. If you believe a child has provided us with personal data without such consent, please contact us at the address in Section 13 and we will delete it.
We apply reasonable administrative, physical, and technical safeguards to protect your data. Transport is encrypted end-to-end (TLS). Credentials are encrypted at rest on our backend. No online service is completely secure; we encourage you to use a strong, unique password for your LibreLinkUp account and to keep your device lock set.
We do not make any solely automated decisions about you that produce legal or similarly significant effects.
We may update this Policy to reflect new features, legal requirements, or service providers. If we make a material change we will notify you in the App or update the "Effective date" above. Your continued use of the App after a change means you accept the updated Policy.
Aytuğ Altınok
Email: altinokaytug@gmail.com
For privacy requests, please include your app's user ID if you have it
(Settings → About → User ID).