One suggested app is being used in Singapore and uses bluetooth vs GPS. They feel confident in it and other measures they taking to leave schools, restaurants and other services open. 5 million people, 1000 confirmed cases and 3 deaths. They say data encrypted and not accessed unless you are infected and opt in, then it shares the data for devices you came near with the ministry of health. They say data older than 21 days erased.

https://globalnews.ca/news/6772753/tech-companies-canada-phone-apps-tracking-coronavirus-spread/