Heart Monitor for Mi Band will periodically connect to your Mi Band 2 and take a heart rate reading which will then be saved to your fitness account for continuous heart rate tracking. The readings are also stored in a local database and can be exported to a CSV file for sharing. The frequency of the recordings can be changed in the app settings. This is not a replacement for the official Mi Fit app, and the Mi Fit app will be required to set up the initial pairing of the band to your phone if it is not already paired.