The Covid-19 (coronavirus) contact tracing API from Apple & Google has yet to be adopted across the board with countries opting to produce their own systems.
However, some countries such as Switzerland are now switching from their own system to the contact tracing API, with other countries such as Portugal & Ireland choosing to adopt the solution from Apple & Google. With Austria and Switzerland announcing they will be switching to it
Countries across the globe that have managed to control the rate of infection are looking for contact tracing apps to prevent local epidemics from becoming pandemic (contain the spread of the virus).
The reason why countries / states around the globe didn’t use the offerings from Apple & Google immediately was due to uncertainty over issues of privacy, control of the data & the fact countries were preparing these systems prior to the launch of Apple & Google’s contact tracing API.
After some countries such as the UK have found major problems with their own systems the API from Apple & Google is now looking much more promising, you can hardly blame them for not jumping straight on board with Apple & Google with the recent scandals over privacy & security with big Tech companies. Hopefully this global crisis may see big tech show a more altruistic side.