CARWatchApp

CARWatch is an open-source research application designed to support accurate and standardized saliva sampling in psychoneuroendocrinological studies. The app enables objective recording of sampling times using barcode scans and automated reminders, reducing reliance on self-reports and improving data validity. Originally developed for assessing the cortisol awakening response (CAR), CARWatch has evolved into a flexible framework supporting a wide range of saliva sampling protocols, including full diurnal cortisol profiling. Researchers can configure study parameters via a companion web interface and distribute QR codes to participants for seamless setup. The app then guides participants through the sampling process, records timestamps, and logs all interactions for later analysis. This app is a research-enablement tool and is not itself the sponsor, operator, or investigator of any specific study. It is used by external research teams and institutions to support the collection of CAR study data. Key features include: - Barcode-based logging of saliva samples for objective timestamping - Flexible alarm scheduling (relative to awakening or fixed clock times) - Support for multi-day and multi-sample study designs - Daily overview of completed, pending, and missed samples - Retrospective logging of missed samples - QR code–based study configuration - Built-in tutorial for participant guidance - Privacy-preserving design with no backend data storage CARWatch is intended for use in scientific studies and is not a medical device. It does not provide medical advice or diagnostics.