When you first access the “SUSTAINABILITY” section on our mobile app, you will need to configure your “UNDO Tracker”. You will then receive a short tutorial of what you can do in the “SUSTAINABILITY” section. At the end of this tutorial, you will be asked if you have a new or refurbished smartphone, so that we can correctly calculate your CO2 emissions. Once you have done this, your “UNDO Tracker” is configured.