Alongside privacy concerns and low usage rates, the incompatibility of coronavirus tracing apps across different countries has been identified as a potential weakness of the technology. For example, if somebody travels from France to Germany and is diagnosed with Covid-19 in Berlin, a warning cannot be sent to his or her contacts through the French system.
The patchwork nature of the technology's rollout is also a major issue in the United States which is not developing a single national app to identify infection chains and trace contacts. Rather, the decision is being left to individual states who have been given the choice to participate in a major partnership by Apple and Google who plan to build the technology into their operating systems.
The effort was announced by both companies on April 10 and from website 9 to 5 Mac, only four U.S. states said they were participating in it as of July 13. On that date, no state had successfully released a contact tracing app and 17 said they would not participate while the rest provided no response regarding their status.
