Out of curiosity, for those that live in major cities, how much memory is this going to take up? From what I understand you have a daily token on your device and a second token which changes approximately every 15 minutes. All these tokens will be stored for 14 days. Also stored will be the token for everyone you come into contact with, the length of time you were in their vicinity, and that too will be stored for 14 days. At a later date, they may store additional information (signal strength- to estimate closeness and maybe weather, such as wind speed, UV levels etc, to estimate increased/decreased risk). Also the latest confirmed COVID cases tokens will be added to your device daily (probably wiping off the previous days).