Combines self reported data and information such as heart rate, from fitness trackers and smart phones to identify potential Covid-19 infections:
Source: Early results from DETECT study suggest fitness trackers and smartwatches can predict COVID-19 infection | Scripps Research
The smart phone app may be downloaded here. The app works with any smart watch phone app that uses Google Fit or Apple Health interfaces. The study has been underway since spring of 2020 and is expected to run for two years. Not only would this app track potential illness (similar to the Kinsa thermometer) but might also be used to eventually measure effectiveness of vaccines.