United States: MTX Group offers New York State contact tracing and monitoring app 

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Frisco, TX-based MTX Group is collaborating with the New York State Department of Health in deploying a coronavirus-monitoring and messaging system enabling New York State to monitor travellers, physicians, and others who come into close contact with anyone with symptoms. The application asks users to check-in through a "digital quarantine", and then sends them a daily alert asking if they have any illness or symptoms. These can then be tracked and sent to health officials. MTX was in discussion about using the app in other states, and  went on to donate the app to all public school districts across the US.

Source: https://www.dallasnews.com/news/public-health/2020/03/11/frisco-technology-company-has-launched-a-disease-monitoring-app-for-coronavirus-cases/