ID 2367: iOS App Development for “CARWatch – An Open-Source Framework for Improving Cortisol Awakening Response Sampling”

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Implementation / Master’s Project

Many studies investigating the cortisol awakening response (CAR) suffer from a lack of precise and objective methods for assessing the awakening and saliva sampling times. Failure to correctly report times or to adhere to the study protocol, which is common in unsupervised real-world studies, can lead to a measurement bias on CAR quantification and can even contribute to erroneous findings in psychoneuroendocrinological (PNE) research.

To address this gap in available methodology, we developed CARWatch. CARWatch is an open-source framework to support objective and low-cost assessment of cortisol samples in unsupervised, real-world environments. Up to now, the CARWatch framework consists of an Android application that schedules sampling times and tracks them by scanning a barcode on the respective sampling tube as well as a web application that provides tools to configure studies, prepare the study materials, and process the log data recorded by the app.

What is missing so far is an iOS application. Thus, the goal of this master’s project is to develop an iOS equivalent of our Android version to complete the CARWatch framework and enable widespread use in the research community.



  • Get familiar with the existing CARWatch framework
  • Develop an iOS app, equivalent to our already existing Android app
  • Integrate the new iOS app into the existing CARWatch framework



  • Interest in psychology, stress research, and open science
  • Knowledge of iOS app development (or willingness to learn such!)


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