Mi Fit

If you own a Mi Band from Xiaomi, from either generation, you will have to connect it to an Android phone that can only be done with the help of an app named Mi Fit. This particular application will be useless unless you have the band as well.
 
If you have both, you will get access to a number of options. Users will be able to set, track, and follow your health and fitness data, will monitor the sleep patterns, set an Early Bird Alarm, share the progress and stats with friends on Facebook, skip lock screens on individual devices, and set your Mi Band to vibrate when you have incoming calls on your phone.