​When users install Bluezone, if there is an infection, users only need to go to the app to know immediately whether or not they have been in contact with this person.

Smartphones installed with Bluezone can communicate with each other within a distance of 2m, recognizing close contact. If F0 appears from data entered by a competent authority, the system will send to all Smartphones in the Bluezone community. At that time, the contact history with F0 will be compared by Bluezone on the smartphones to analyze and compare. If there is a match, the app will immediately warn users of the risk of Covid-19 infection. Bluezone can also help warn people of F2 group (close contact with F1).

Bluezone has 05 important characteristics. Firstly, data security: The app only stores data on users' smartphones, not transferring it to the system. Only when users become F0 do they need to share this data with authorities. Second, no data collection about the location of the users. Third, anonymity: People join the community anonymously with others; only authorized Health agencies can know those infected and suspected by close contact with people infected with Covid-19. Fourth, transparency: The project is opened source code under GPL 3.0 copyright; users of countries all over the world are free to learn about system activity at source code, free to use, research, modify and share. Fifth, no battery drain: Bluezone uses Bluetooth Low Energy technology so it is possible to turn on Bluetooth all day but use only about 10% of the battery.