BATON ROUGE, La. (AP) — Researchers at Louisiana State University have created a cellphone app to track exposures to COVID-19. The Advocate reports the GeauxTrace contact tracing app uses the signal strength from Bluetooth software to assess the distance between cellphones. Users who were in the vicinity of someone who recently tested positive for COVID-19 are informed of the possible exposure. LSU electrical and computer science professor Lu Peng developed the university’s app with a group of students using an $890,000 grant from the National Institutes of Health.