Contact-tracing allows individuals to be alerted if they have encountered affected people and prevent the spread of SARS-CoV-2. The research consortium DP-3T is developing a distributed approach to do so while preserving the privacy of its users. Using Bluetooth technology, the distance with other people is only computed and stored in the local phone memory, therefore not transmitted to third-party companies or governments.

The accuracy of the contact tracing measure depends on how the user carries their phone: in the front or back pocket, in the hands or in a purse.

Indie-Pocket is able to detect where you carry your phone using only its integrated accelerometer sensor. Leveraging on machine learning and previously collected data from voluntary participants, the algorithm can tell with 95% accuracy in which pocket your phone is located. This can be used by contact-tracing systems such as DP-3T, the Google-Apple joint initiative, or PEPP-PT, to enhance the precision of their measurement.