Technology may be part of the solution to stopping the spread of COVID-19, but apps alone will not save us. As more states develop COVID exposure notification apps, institutions and the people they serve should remain skeptical and remember the bigger picture. This is still experimental, unproven technology, both in terms of how it works under the hood and how humans will interact with it. And even the best-designed app will be no substitute for public health basics like widespread testing and interview-based contact tracing.
On top of that, any benefits of this technology will be unevenly distributed. Any app-based or smartphone-based solution will systematically miss the groups least likely to have a cellphone and more at risk of COVID-19 and in need of resources: in the United States, that includes elderly people, people without housing, and those living in rural communities.