App that Maps COVID-19 Hotspots


The CovidInArea app, developed by the Hong Kong University of Science and Technology (HKUST), combines and visualizes open data while protecting user privacy on mobile devices. The Department of Health (DoH) of the HKSAR Government provided a list of buildings visited by cases who tested positive for the SARS-CoV-2 virus in the past 14 days (herein referred to as “incident places”) as an easily accessible heatmap, providing a free location-based tool for users to understand their risk due to proximity with the incident places.

The software, which features a real-time heatmap for quickly browsing the locations of the occurrence spots, was conceived and built by a team under the direction of Prof. Gary CHAN Shueng-Han from the Department of Computer Science and Engineering.


Contrary to other platforms and apps now in use, which typically needs users to manually verify the locations, CovidInArea performs the verification automatically by offering real-time GPS support for mobile users. It is the first publicly accessible COVID-19-related software created by a university for use throughout Hong Kong that is both Google Play Store and Apple App Store compatible.


Based on data that is regularly updated in accordance with the government’s associated daily information release, the heatmap pinpoints incident places provided by DoH. Users may quickly obtain a thorough understanding of the incident locations—indicated by colors of various temperatures on the heatmap—by zooming in and out. This allows them to make informed judgments about their daily activities, route planning, and maintaining safe distances.


CovidInArea doesn’t require user registration and only collects GPS location information, protecting user privacy. The GPS position, once used, is promptly deleted without storage at any time, and all calculations are performed with results shown locally on the user’s phone. Additionally, users are able to readily visualize the number of occurrences put in their vicinity in real-time in a chart over the course of several days when GPS is turned on. The app also displays the overall proximity danger via a color radar chart, taking into account the distance, users’ dwell duration, and the number of areas of incidence nearby:


  • Red: Overall high sustained contact with incident places. Recommended to reduce high-risk places, manage health and take voluntary testing if needed.
  • Yellow: Medium risk. Be cautious. Plan safe paths to reduce risk.
  • Green: Low risk. Stay vigilant.

According to Prof. Gary Chan, the app offers a timely and user-friendly reference on incident places to help citizens stay aware of their surroundings and take precautions if necessary to proactively reduce the infection risk while commuting because the number of confirmed cases in Hong Kong has remained high recently.


Using CovidInArea, he continued, users may plan daily travels, manage their health, and maintain a safe distance from the scene of incidents. The professor also praised the administration for making the data available to the public so that everyone may work together to combat COVID-19.


The creation of cutting-edge, exact sensing and positioning technologies for smart applications is a specialty of Prof. Gary CHAN Sheung-Han. He and the government collaborated to create geofencing technology, which is used in the StayHomeSafe app to implement regional home quarantine orders. Additionally, he developed a smartphone software that effectively searches the city for missing dementia patients while protecting their privacy by detecting registered Bluetooth signals. Many malls and other locations have also implemented his indoor navigation technology.