The people behind this website created a way to rank the social distancing practices of different places across the United States from A to F based on GPS data from cell phones on a daily basis. They think it can be used in a way to “measure and understand the efficacy of social distancing initiatives at the local level.” It sits at the intersection of important epidemiological data and new, possibly concerning, technology.
https://www.unacast.com/covid19/social-distancing-scoreboard