How to disable your fingerprint scanner when you sleep [Exclusive]

Fingerprint scanners have almost become an essential part of a modern smartphone. The benefits are evident: you don't need to enter a password or pin or pattern each time you unlock your phone, without compromising with its security and privacy. The latter part though, is somewhat invalidated by the fact that while you are asleep, anyone around you can get your finger to register its print on the fingerprint scanner, and thus unlock the phone.

(Unless you are a ninja, and even the slightest of the touches can wake you up, you won't even know that someone had accessed your phone while you were drooling in your sleep. Even if you are a ninja, you would still have to chase down your friend who now has your unlocked phone with him.)

I haven't seen any smartphone yet, that comes with a feature built in, that allows you to disable your fingerprint scanner during specific periods of time. If you are as paranoid as me, this little guide will be quite useful to you.

If you have searched for this problem in the past, you might have encountered solutions that require you to install an ad ridden application, or deleting your fingerprints every night, and registering them again in the morning. I'm sure you would find this solution to be much more elegant.

Once you are done with the below steps,
 you'll be able to lock your device using the
Lock icon, and your fingerprint won't work!

How to temporarily disable your fingerprint scanner when you sleep

1. Install Lock app from the Play Store. There are several other apps that we can use for the same purpose, but this app is 69 KB in size, comes with a nice lock icon, is free and has no ads. What else can we ask for!
2. Once you install it, add a shortcut to the app to your home screen. (Holding the app icon in the app drawer and then dragging it to the home screen does it for most Android variants.)
3. Tap on the app icon. This will cause a prompt to appear, asking you to add the app as a device adminstrator. Any app that attempts to turn off and lock your screen, needs to be a device administrator on Android smartphones, so, tap the "Activate this device administrator" option.
4. As soon as you activate the device administrator, your screen will turn off and locked. You can try using your fingerprint scanner now. The screen will turn on, but it will ask you to enter your pin/password/pattern.
5. That's it. Every night before you sleep, use the Lock app shortcut on your homescreen to lock your screen securely. If you lock your phone the usual way (by using your power button), the fingerprint scanner will work as expected.

Once you install the app, open it,
 and tap "Activate this
device administrator" on
the prompt that appears

When you have locked the app
using the Lock shortcut, you'll
have to enter your
pin or password or pattern

I know you still have to remember to use the app shortcut every night, but it's still just a one tap thing. If you are an advanced user, you can use Tasker or MacroDroid to open the Lock app daily at the time you usually sleep.