Here's how you can download the Fingerprint Scanner Lock app free for Android devices.
1. Go to the Google Play page for the free app Fingerprint Scanner Lock.
2. Tap the Install button.
Here's a description of Fingerprint Scanner Lock:
"HOW TO USE:
Go to Settings and set the number of scans to unlock.
Give your phone to an unsuspecting friend and tell him/her to unlock the phone.
He will fail.
Then since you know number of times to unlock it. Prove to him you can unlock it.
Has 4 different themes to choose. Ice cream sandwich , Jellybean, Iphone 5 and iphone 4S themes.
You can set it to appear as phone unlock so it will start up immediately after your unlock the phone. By default it is not checked. if you want this feature go to menu item settings and check set as lock screen.
Customization options - You set the rules and hence you are the only one who knows the trick to unlock."