  The COVID-19 pandemic has fueled the development of smartphone applications
to assist disease management. Many "corona apps" require widespread adoption to
be effective, which has sparked public debates about the privacy, security, and
societal implications of government-backed health applications. We conducted a
representative online study in Germany (n = 1,003), the US (n = 1,003), and
China (n = 1,019) to investigate user acceptance of corona apps, using a
vignette design based on the contextual integrity framework. We explored apps
for contact tracing, symptom checks, quarantine enforcement, health
certificates, and mere information. Our results provide insights into data
processing practices that foster adoption and reveal significant differences
between countries, with user acceptance being highest in China and lowest in
the US. Chinese participants prefer the collection of personalized data, while
German and US participants favor anonymity. Across countries, contact tracing
is viewed more positively than quarantine enforcement, and technical
malfunctions negatively impact user acceptance.
