Last updated: 8 July 2026

Portabiles GmbH provides the CAR Watch mobile application, package name de.fau.cs.mad.carwatch, as a free application. This Service is provided at no cost and is intended for use in research studies that require accurate timing and documentation of biosampling procedures, for example cortisol awakening response studies, diurnal sampling protocols, or other biosampling studies where sampling adherence and timing are important.

This Privacy Policy explains how CAR Watch accesses, collects, stores, uses, and shares information when you use the app.

Purpose of CAR Watch

CAR Watch is designed to support study participants during biosampling studies. Depending on the study configuration, the app may be used to:

  • configure a study protocol by scanning a QR code;
  • remind participants to take saliva or other biological samples;
  • record awakening times, either by self-report or alarm-based interaction;
  • scan barcodes attached to sampling tubes;
  • log the time at which a sample was scanned or marked as taken;
  • export time log files for later analysis by a study coordinator.

CAR Watch does not analyze biological samples. It does not measure cortisol or other biomarkers directly. It does not include questionnaires directly in the app. It does not track sampling compliance in real time on a server.

Information We Collect

CAR Watch does not require users to create an account.

The app may store or process the following information locally on your device, depending on the study setup:

Study Configuration Data

When you scan a study QR code, the app may store configuration information such as:

  • study name or study identifier;
  • participant code or pseudonymous participant identifier;
  • number of sampling days;
  • number of samples per day;
  • planned sampling times;
  • reminder/alarm settings;
  • contact email address of the study coordinator, if configured.

The app does not require your real name, email address, address, phone number, or other direct identifying information unless such information is intentionally encoded by the study organizer in the study materials.

Sampling and Time Log Data

During use, CAR Watch may store metadata such as:

  • awakening time;
  • alarm times;
  • sampling reminder times;
  • barcode scan times;
  • barcode values or sample identifiers;
  • whether a sample was scanned, missed, delayed, or manually recorded;
  • app interaction timestamps relevant to the study procedure;
  • exported log files generated from these records.

These data are used to document whether samples were taken at the intended time and to support later evaluation of sampling adherence.

Camera Access for QR Codes and Barcodes

CAR Watch may request access to the device camera to scan QR codes and barcodes. Camera access is used only for scanning study setup codes and sample tube barcodes.

CAR Watch does not use the camera to record photos or videos, and camera images are not stored or transmitted by the app.

Optional Sensor Data

Depending on the version of the app and the study configuration, CAR Watch may include optional or experimental features such as:

  • recording of light sensor readings during sampling periods.

These features are only used where enabled by the study setup and permitted by the user or device settings. Such data, if used, are intended to improve the interpretation of awakening and sampling timing.

Technical and Diagnostic Data

In case of errors, crashes, or technical problems, diagnostic information may be collected through platform services such as Google Play Services or Android system services. This may include:

  • device model;
  • operating system version;
  • app version;
  • time and date of the error;
  • crash logs or technical diagnostics;
  • general app configuration at the time of the error.

These data are used only to maintain app functionality, identify bugs, and improve reliability.

Information We Do Not Collect

CAR Watch itself does not require or directly collect:

  • user accounts;
  • passwords;
  • payment information;
  • GPS location;
  • contact lists;
  • photos or videos;
  • audio recordings;
  • questionnaire responses;
  • biological sample values;
  • cortisol values or laboratory results.

CAR Watch does not store personal data on Portabiles GmbH servers as part of normal app use. The data generated by the app are primarily stored locally on the smartphone until exported or deleted.

How We Use Information

Information processed by CAR Watch is used to:

  • configure the study protocol on the device;
  • schedule and trigger sampling reminders;
  • document sampling times;
  • document awakening times;
  • enable barcode-based assignment of samples and timestamps;
  • generate log files for scientific analysis;
  • troubleshoot app functionality;
  • improve the app and related research tools.

Storage of Data

CAR Watch stores study configuration data and time log data locally on the user’s device.

CAR Watch does not automatically upload log files to Portabiles GmbH servers during normal app use. At the end of a study, participants may export or share log files with the study coordinator, for example by email or another sharing method available on the device.

Once log files are sent to a study coordinator, research institution, or other third party, further processing of those files is governed by the study information, consent documents, and privacy policies provided by the respective study organizer.

Sharing of Data

CAR Watch does not sell user data.

CAR Watch may share or transmit data only in the following cases:

User-Initiated Export

Users may actively export or share log files with a study coordinator. The recipient email address may be prefilled if configured in the study setup.

Study Coordinator or Research Institution

If you participate in a study, exported log files may be processed by the responsible study coordinator or research institution. Portabiles GmbH does not control how the study coordinator further processes exported files.

Third-Party Services

CAR Watch may rely on third-party services that can process technical information necessary for app functionality, diagnostics, or platform integration. These may include:

  • Google Play Services;
  • Google Fit, if enabled and used in the study setup;
  • Android system sharing functions or email apps selected by the user for exporting log files.

Third-party services process data according to their own privacy policies.

Data Retention

Data stored locally in CAR Watch remain on the device until they are deleted by the user, deleted through app functionality, cleared through Android system settings, or removed by uninstalling the app.

Exported log files remain under the control of the recipient to whom they were sent, such as the study coordinator or research institution.

Technical diagnostic data, if collected through platform services, may be retained according to the retention rules of the respective platform provider.

Data Deletion

CAR Watch does not require users to create an account. Portabiles GmbH does not automatically receive or store CAR Watch study data on its servers. Therefore, Portabiles GmbH usually does not possess app-generated study data that could be deleted on behalf of the user.

Users can delete locally stored CAR Watch data directly on their device by:

  1. deleting logs within CAR Watch, where this function is available;
  2. clearing the app’s storage in the Android system settings;
  3. uninstalling CAR Watch from the device.

If CAR Watch is used on a study phone that is passed from one participant to another, the previous participant’s logs should be deleted before the app is registered for the next participant.

If log files have already been exported or sent to a study coordinator or research institution, deletion requests must be directed to the responsible study coordinator or institution named in the study information or consent documents. Portabiles GmbH can only delete data that are actually under its own control.

For questions about the deletion process, contact:

contact@portabiles.de

Use the subject line:

Data deletion question – CAR Watch

Security

We use commercially reasonable technical and organizational measures to protect information processed by CAR Watch. However, no method of electronic storage or transmission is completely secure. We cannot guarantee absolute security.

Users should only export log files to trusted study coordinators or research contacts.

Children’s Privacy

CAR Watch is not directed to children under the age of 13.

If CAR Watch is used in a research study involving minors, the responsible study organizer must obtain the required consent or approval according to applicable laws, ethics requirements, and institutional procedures.

We do not knowingly collect personally identifiable information from children under 13 through CAR Watch. If we become aware that such information has been provided to us without appropriate consent, we will take steps to delete it.

Links to Other Sites or Services

CARWatch or related study materials may contain links to external websites, such as project websites, GitHub repositories, study information pages, or third-party support pages. These external sites are not operated by Portabiles GmbH. We are not responsible for the content, privacy policies, or practices of third-party websites or services.

Open-Source Components and Project Information

CARWatch is part of the CARWatch framework. The framework includes smartphone applications and a study manager for configuring studies, preparing study materials, and processing exported time logs.

Project information and source code may be available through the CARWatch project website and GitHub repositories.

Changes to This Privacy Policy

We may update this Privacy Policy from time to time. Updates will be posted on this page. Changes are effective when posted.

Contact Us

For questions about this Privacy Policy or requests related to your data, contact:

Portabiles GmbH
Email: contact@portabiles.de

For study-specific questions, including questions about exported log files, sample timing data, or research participation, contact the study coordinator named in your study information materials.