When collecting saliva samples in field studies, participant compliance is a critical factor for the reliability and validity of the collected data. In particular, deviations from planned collection times are potentially a source of unwanted confounding variance. SalivaTracker is a small, useful smartphone app for documenting collection time points when collecting saliva samples in the field. SalivaTracker is currently only available for Android (version 5.0 or later; Lollipop).

The app captures timestamps as samples are collected and sends them to a server you specify when an Internet connection is available. In addition, the app prompts users to take photos of the collected samples. These photos are stored locally in the smartphone's gallery under Pictures and can then be exported.

Server setup:

  1. When you use the app for the first time, you will be prompted to scan the server address.
  2. To do this, the app uses the QR code reader from Zxing Team.
  3. The app automatically redirects you to the download if you do not have the QR code reader installed.
  4. Create a QR code with the address of your server [address + location] and read it with the QR-Code Reader.
  5. Press Save.
  6. The home screen now displays "Server connected".

Installing the app:

  1. Using your Android phone, download the APK from this website [see Download].
  2. Open the download and confirm the warning messages to start the installation.
  3. Grant the app access to your camera.




Antonia Vehlen,