Here's a small modification in the Mi Fit app.
Have you ever freaked out when your friend/sibling grabbed your phone and unlocked it by walking close to your Mi Band? But now you can set the distance within which your Mi Band will unlock!
So let's see how it all works!
Step 1: Open the Mi Fit app
Step 2: Enter the menu (the 3 dots in the top right corner)
Step 3: Go to Settings/Settings submenu
Step 4: Touch Mi Band
Step 5: Click "Unlock device using band / Unlock screen lock"
Step 6: Click on the image 10 times (continuously)
Step 7: Now you have to set 3 options, as you can see in the picture below
Since the menu is in Chinese, I will provide them in English as well:
Close To Device / Close To Phone
With in 1 Metre / Within 1 Metre
With in 3 Metre / Within 3 Metres
Enter the desired distance!!
Note: Follow the same procedure for all Mi Fit versions available for download from the Mi App Store or Google Play Store
Enjoy the new setting options!
source: http://en.miui.com/forum.php?mod=viewthread&tid=219372&highlight=distance
